Inbred maize line PH8DB

ABSTRACT

An inbred maize line, designated PH8DB, the plants and seeds of inbred maize line PH8DB, methods for producing a maize plant, either inbred or hybrid, produced by crossing the inbred maize line PH8DB with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH8DB with another maize line or plant and to methods for producing a maize plant containing in its genetic material one or more transgenes and to the transgenic maize plants produced by that method. This invention also relates to inbred maize lines derived from inbred maize line PH8DB, to methods for producing other inbred maize lines derived from inbred maize line PH8DB and to the inbred maize lines derived by the use of those methods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/271,166, now U.S. Pat. No. 6,881,880, filed Oct. 15, 2002, which is anon-provisional of U.S. patent application Ser. No. 60/354,092 filedJan. 31, 2002, the contents of which are hereby incorporated byreference in their entirety.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relatingto an inbred maize line designated PH8DB.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine, in a single variety or hybrid,various desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and plant and ear height, is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is sib-pollinated when individuals within the same familyor line are used for pollination. A plant is cross-pollinated if thepollen comes from a flower on a different plant from a different familyor line. The terms “cross-pollination” and “out-cross” as used herein donot include self-pollination or sib-pollination.

Plants that have been self-pollinated and selected for type for manygenerations become homozygous at almost all gene loci and produce auniform population of true breeding progeny. A cross between twodifferent homozygous lines produces a uniform population of hybridplants that may be heterozygous for many gene loci. A cross of twoplants, each heterozygous at a number of gene loci, will produce apopulation of hybrid plants that differ genetically and will not beuniform.

Maize (zea mays L.), often referred to as corn in the United States, canbe bred by both self-pollination and cross-pollination techniques. Maizehas separate male and female flowers on the same plant, located on thetassel and the ear, respectively. Natural pollination occurs in maizewhen wind blows pollen from the tassels to the silks that protrude fromthe tops of the ears.

A reliable method of controlling male fertility in plants offers theopportunity for improved plant breeding. This is especially true fordevelopment of maize hybrids, which relies upon some sort of malesterility system. There are several ways in which a maize plant can bemanipulated so that it is male sterile. These include use of manual ormechanical emasculation (or detasseling), use of cytoplasmic genetic ornuclear genetic male sterility, use of gametocides and the like.

Hybrid maize seed is typically produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twomaize inbreds are planted in a field, and the pollen-bearing tassels areremoved from one of the inbreds (female). Provided that there issufficient isolation from sources of foreign maize pollen, the ears ofthe detasseled inbred will be fertilized only from the other inbred(male), and the resulting seed is therefore hybrid and will form hybridplants.

The laborious detasseling process can be avoided by using cytoplasmicmale-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as aresult of factors resulting from the cytoplasmic, as opposed to thenuclear, genome. Thus, this characteristic is inherited exclusivelythrough the female parent in maize plants, since only the femaleprovides cytoplasm to the fertilized seed. CMS plants are fertilizedwith pollen from another inbred that is not male-sterile. Pollen fromthe second inbred may or may not contribute genes that make the hybridplants male-fertile. The same hybrid seed, a portion produced fromdetasseled fertile maize and a portion produced using the CMS system,can be blended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Theseand all patents, patent applications and publications referred to hereinare incorporated by reference. In addition to these methods, Albertsenet al., of Pioneer Hi-Bred, U.S. Pat. No. 5,432,068, have developed asystem of nuclear male sterility which includes: identifying a genewhich is critical to male fertility; silencing this native gene which iscritical to male fertility; removing the native promoter from theessential male fertility gene and replacing it with an induciblepromoter; inserting this genetically engineered gene back into theplant; and thus creating a plant that is male sterile because theinducible promoter is not “on” resulting in the male fertility gene notbeing transcribed. Fertility is restored by inducing, or turning “on”,the promoter, which in turn allows the gene that confers male fertilityto be transcribed.

These, and the other methods of conferring genetic male sterility in theart, each possess their own benefits and drawbacks. Some other methodsuse a variety of approaches such as delivering into the plant a geneencoding a cytotoxic substance associated with a male tissue specificpromoter or an antisense system in which a gene critical to fertility isidentified and an antisense to that gene is inserted in the plant (see:Fabinjanski, et al. EPO 89/3010153.8 Publication No. 329,308 and PCTApplication No. PCT/CA90/00037 published as WO 90/08828).

Another system for controlling male sterility makes use of gametocides.Gametocides are not a genetic system, but rather a topical applicationof chemicals. These chemicals affect cells that are critical to malefertility. The application of these chemicals affects fertility in theplants only for the growing season in which the gametocide is applied(see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application of thegametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach and it is not appropriate in allsituations.

Development of Maize Inbred Lines

The use of male sterile inbreds is but one factor in the production ofmaize hybrids. Plant breeding techniques known in the art and used in amaize plant breeding program include, but are not limited to, recurrentselection, backcrossing, pedigree breeding, restriction fragment lengthpolymorphism enhanced selection, genetic marker enhanced selection,making double haploids, and transformation. Often a combination of thesetechniques are used. The development of maize hybrids in a maize plantbreeding program requires, in general, the development of homozygousinbred lines, the crossing of these lines, and the evaluation of thecrosses.

Maize plant breeding programs combine the genetic backgrounds from twoor more inbred lines or various other germplasm sources into breedingpopulations from which new inbred lines are developed by selfing andselection of desired phenotypes. The new inbreds are crossed with otherinbred lines and the hybrids from these crosses are evaluated todetermine which of those have commercial potential. Plant breeding andhybrid development, as practiced in a maize plant breeding programdeveloping significant genetic advancement, are expensive and timeconsuming processes.

Pedigree breeding starts with the crossing of two genotypes, such as twoelite inbred lines, each of which may have one or more desirablecharacteristics that is lacking in the other or which complements theother. If the two original parents do not provide all the desiredcharacteristics, other sources can be included in the breedingpopulation. In the pedigree method, superior plants are selfed andselected in successive filial generations. In the succeeding filialgenerations the heterozygous condition gives way to homogeneous lines asa result of self-pollination and selection. Typically in the pedigreemethod of breeding, five or more successive filial generations ofselfing and selection is practiced: F₁→F₂; F₂→F₃; F₃→F₄; F₄→F₅, etc.After a sufficient amount of inbreeding, successive filial generationswill serve to increase seed of the developed inbred. Preferably, aninbred line comprises homozygous alleles at about 95% or more of itsloci.

Backcrossing can be used to improve an inbred line and a hybrid that ismade using those inbreds. Backcrossing can be used to transfer aspecific desirable trait from one line, the donor parent, to an inbredcalled the recurrent parent which has overall good agronomiccharacteristics yet lacks that desirable trait. This transfer of thedesirable trait into an inbred with overall good agronomiccharacteristics can be accomplished by first crossing a recurrent parentand a donor parent (non-recurrent parent). The progeny of this cross isthen mated back to the recurrent parent followed by selection in theresultant progeny for the desired trait to be transferred from thenon-recurrent parent as well as selection for the characteristics of therecurrent parent. Typically after four or more backcross generationswith selection for the desired trait and the characteristics of therecurrent parent, the progeny will contain essentially all genes of therecurrent parent except for the genes controlling the desired trait.However, the number of backcross generations can be less if molecularmarkers are used during selection or elite germplasm is used as thedonor parent. The last backcross generation is then selfed to give purebreeding progeny for the gene(s) being transferred. Backcrossing canalso be used in conjunction with pedigree breeding to develop new inbredlines. For example, an F1 can be created that is backcrossed to one ofits parent lines to create a BC1, BC2, BC3, etc. Progeny are selfed andselected so that the newly developed inbred has many of the attributesof the recurrent parent and some of the desired attributes of thenon-recurrent parent. This approach leverages the value and strengths ofthe recurrent parent for use in new hybrids and breeding which has verysignificant value for a breeder.

Recurrent selection is a method used in a plant breeding program toimprove a population of plants. The method entails individual plantscross pollinating with each other to form progeny which are then grown.The superior progeny are then selected by any number of methods, whichinclude individual plant, half-sib progeny, full-sib progeny, selfedprogeny and topcrossing. The selected progeny are cross pollinated witheach other to form progeny for another population. This population isplanted and again superior plants are selected to cross pollinate witheach other. Recurrent selection is a cyclical process and therefore canbe repeated as many times as desired. The objective of recurrentselection is to improve the traits of a population. The improvedpopulation can then be used as a source of breeding material to obtaininbred lines to be used in hybrids or used as parents for a syntheticcultivar. A synthetic cultivar is the resultant progeny formed by theintercrossing of several selected inbreds. Mass selection is a usefultechnique when used in conjunction with molecular marker enhancedselection.

Mutation breeding is one of the many methods of introducing new traitsinto inbred lines. Mutations that occur spontaneously or areartificially induced can be useful sources of variability for a plantbreeder. The goal of artificial mutagenesis is to increase the rate ofmutation for a desired characteristic. Mutation rates can be increasedby many different means including temperature, long-term seed storage,tissue culture conditions, radiation; such as X-rays, Gamma rays (e.g.cobalt 60 or cesium 137), neutrons, (product of nuclear fission byuranium 235 in an atomic reactor), Beta radiation (emitted fromradioisotopes such as phosphorus 32 or carbon 14), or ultravioletradiation (preferably from 2500 to 2900 nm), or chemical mutagens (suchas base analogues (5-bromo-uracil), related compounds (8-ethoxycaffeine), antibiotics (streptonigrin), alkylating agents (sulfurmustards, nitrogen mustards, epoxides, ethylenamines, sulfates,sulfonates, sulfones, lactones), azide, hydroxylamine, nitrous acid, oracridines. Once a desired trait is observed through mutagenesis thetrait may then be incorporated into existing germplasm by traditionalbreeding techniques. Details of mutation breeding can be found in“Principals of Cultivar Development” Fehr, 1993 Macmillan PublishingCompany the disclosure of which is incorporated herein by reference.

Molecular markers, which includes markers identified through the use oftechniques such as Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats(SSRs) and Single Nucleotide Polymorphisms (SNPs), may be used in plantbreeding methods. One use of molecular markers is Quantitative TraitLoci (QTL) mapping. QTL mapping is the use of markers, which are knownto be closely linked to alleles that have measurable effects on aquantitative trait. Selection in the breeding process is based upon theaccumulation of markers linked to the positive effecting alleles and/orthe elimination of the markers linked to the negative effecting allelesfrom the plant's genome.

Molecular markers can also be used during the breeding process for theselection of qualitative traits. For example, markers closely linked toalleles or markers containing sequences within the actual alleles ofinterest can be used to select plants that contain the alleles ofinterest during a backcrossing breeding program. The markers can also beused to select for the genome of the recurrent parent and against thegenome of the donor parent. Using this procedure can minimize the amountof genome from the donor parent that remains in the selected plants. Itcan also be used to reduce the number of crosses back to the recurrentparent needed in a backcrossing program. The use of molecular markers inthe selection process is often called genetic marker enhanced selection.

The production of double haploids can also be used for the developmentof inbreds in the breeding program. Double haploids are produced by thedoubling of a set of chromosomes (1 N) from a heterozygous plant toproduce a completely homozygous individual. For example, see Wan et al.,“Efficient Production of Doubled Haploid Plants Through ColchicineTreatment of Anther-Derived Maize Callus”, Theoretical and AppliedGenetics, 77:889-892, 1989. This can be advantageous because the processomits the generations of selfing needed to obtain a homozygous plantfrom a heterozygous source. This can be advantageous because the processomits the generations of selfing needed to obtain a homozygous plantfrom a heterozygous source.

Development of Maize Hybrids

A single cross maize hybrid results from the cross of two inbred lines,each of which has a genotype that complements the genotype of the other.The hybrid progeny of the first generation is designated F₁. In thedevelopment of commercial hybrids in a maize plant breeding program,only the F₁ hybrid plants are sought. F₁ hybrids are more vigorous thantheir inbred parents. This hybrid vigor, or heterosis, can be manifestedin many polygenic traits, including increased vegetative growth andincreased yield.

The development of a maize hybrid in a maize plant breeding programinvolves three steps: (1) the selection of plants from various germplasmpools for initial breeding crosses; (2) the selfing of the selectedplants from the breeding crosses for several generations to produce aseries of inbred lines, which, although different from each other, breedtrue and are highly uniform; and (3) crossing the selected inbred lineswith different inbred lines to produce the hybrids. During theinbreeding process in maize, the vigor of the lines decreases. Vigor isrestored when two different inbred lines are crossed to produce thehybrid. An important consequence of the homozygosity and homogeneity ofthe inbred lines is that the hybrid between a defined pair of inbredswill always be the same. Once the inbreds that give a superior hybridhave been identified, the hybrid seed can be reproduced indefinitely aslong as the homogeneity of the inbred parents is maintained.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F₁ progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybridsare crossed again (A×B)×(C×D). A three-way cross hybrid is produced fromthree inbred lines where two of the inbred lines are crossed (A×B) andthen the resulting F₁ hybrid is crossed with the third inbred (A×B)×C.Much of the hybrid vigor and uniformity exhibited by F₁ hybrids is lostin the next generation (F₂). Consequently, seed produced from hybrids isnot used for planting stock.

Hybrid seed production requires elimination or inactivation of pollenproduced by the female parent. Incomplete removal or inactivation of thepollen provides the potential for self-pollination. This inadvertentlyself-pollinated seed may be unintentionally harvested and packaged withhybrid seed. Also, because the male parent is grown next to the femaleparent in the field there is the very low probability that the maleselfed seed could be unintentionally harvested and packaged with thehybrid seed. Once the seed from the hybrid bag is planted, it ispossible to identify and select these self-pollinated plants. Theseself-pollinated plants will be genetically equivalent to one of theinbred lines used to produce the hybrid. Though the possibility ofinbreds being included hybrid seed bags exists, the occurrence is rarebecause much care is taken to avoid such inclusions. It is worth notingthat hybrid seed is sold to growers for the production of grain orforage and not for breeding or seed production.

These self-pollinated plants can be identified and selected by oneskilled in the art due to their decreased vigor when compared to thehybrid. Inbreds are identified by their less vigorous appearance forvegetative and/or reproductive characteristics, including shorter plantheight, small ear size, ear and kernel shape, cob color, or othercharacteristics.

Identification of these self-pollinated lines can also be accomplishedthrough molecular marker analyses. See, “The Identification of FemaleSelfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology”, Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, pp. 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self pollinated line can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, “Identification of Atypical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis” Sarca, V. et al., Probleme de GeneticaTeoritica si Aplicata Vol. 20 (1) p. 29-42.

As is readily apparent to one skilled in the art, the foregoing are onlysome of the various ways by which the inbred can be obtained by thoselooking to use the germplasm. Other means are available, and the aboveexamples are illustrative only.

Maize is an important and valuable field crop. Thus, a continuing goalof plant breeders is to develop high-yielding maize hybrids that areagronomically sound based on stable inbred lines. The reasons for thisgoal are obvious: to maximize the amount of grain produced with theinputs used and minimize susceptibility of the crop to pests andenvironmental stresses. To accomplish this goal, the maize breeder mustselect and develop superior inbred parental lines for producing hybrids.This requires identification and selection of genetically uniqueindividuals that occur in a segregating population. The segregatingpopulation is the result of a combination of crossover events plus theindependent assortment of specific combinations of alleles at many geneloci that results in specific genotypes. The probability of selectingany one individual with a specific genotype from a breeding cross isinfinitesimal due to the large number of segregating genes and theunlimited recombinations of these genes, some of which may be closelylinked. However, the genetic variation among individual progeny of abreeding cross allows for the identification of rare and valuable newgenotypes. These new genotypes are neither predictable nor incrementalin value, but rather the result of manifested genetic variation combinedwith selection methods, environments and the actions of the breeder.Once identified, it is possible to utilize routine and predictablebreeding methods to develop progeny that retain the rare and valuablenew genotypes developed by the initial breeder.

Even if the entire genotypes of the parents of the breeding cross werecharacterized and a desired genotype known, only a few if anyindividuals having the desired genotype may be found in a largesegregating F₂ population. It would be very unlikely that a breeder ofordinary skill in the art would able to recreate the same line twicefrom the very same original parents as the breeder is unable to directhow the genomes combine or how they will interact with the environmentalconditions. This unpredictability results in the expenditure of largeamounts of research resources in the development of a superior new maizeinbred line. Once such a line is developed its value to society issubstantial since it is important to advance the germplasm base as awhole in order to maintain or improve traits such as yield, diseaseresistance, pest resistance and plant performance in extreme weatherconditions.

A breeder uses various methods to help determine which plants should beselected from the segregating populations and ultimately which inbredlines will be used to develop hybrids for commercialization. In additionto the knowledge of the germplasm and other skills the breeder uses, apart of the selection process is dependent on experimental designcoupled with the use of statistical analysis. Experimental design andstatistical analysis are used to help determine which plants, whichfamily of plants, and finally which inbred lines and hybrid combinationsare significantly better or different for one or more traits ofinterest. Experimental design methods are used to assess error so thatdifferences between two inbred lines or two hybrid lines can be moreaccurately determined. Statistical analysis includes the calculation ofmean values, determination of the statistical significance of thesources of variation, and the calculation of the appropriate variancecomponents. Either a five or a one percent significance level iscustomarily used to determine whether a difference that occurs for agiven trait is real or due to the environment or experimental error. Oneof ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see Fehr, Walt, Principles of CultivarDevelopment, p. 261-286 (1987) which is incorporated herein byreference. Mean trait values may be used to determine whether traitdifferences are significant, and preferably the traits are measured onplants grown under the same environmental conditions.

Combining ability of a line, as well as the performance of the line perse, is a factor in the selection of improved maize inbreds. Combiningability refers to a line's contribution as a parent when crossed withother lines to form hybrids. The hybrids formed for the purpose ofselecting superior lines are designated as test crosses. One way ofmeasuring combining ability is by using breeding values. Breeding valuesare based in part on the overall mean of a number of test crosses. Thismean is then adjusted to remove environmental effects and it is adjustedfor known genetic relationships among the lines.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maize line,designated PH8DB. This invention thus relates to the seeds of inbredmaize line PH8DB, to the plants of inbred maize line PH8DB, to plantparts of inbred maize line PH8DB, to methods for producing a maize plantproduced by crossing the inbred maize line PH8DB with another maizeplant, including a plant that is part of a synthetic or naturalpopulation, and to methods for producing a maize plant containing in itsgenetic material one or more transgenes and to the transgenic maizeplants and plant parts produced by that method. This invention alsorelates to inbred maize lines and plant parts derived from inbred maizeline PH8DB, to methods for producing other inbred maize lines derivedfrom inbred maize line PH8DB and to the inbred maize lines and theirparts derived by the use of those methods. This invention furtherrelates to hybrid maize seeds, plants, and plant parts produced bycrossing the inbred line PH8DB with another maize line.

Definitions

Certain definitions used in the specification are provided below. Alsoin the examples that follow, a number of terms are used herein. In orderto provide a clear and consistent understanding of the specification andclaims, including the scope to be given such terms, the followingdefinitions are provided. NOTE: ABS is in absolute terms and % MN ispercent of the mean for the experiments in which the inbred or hybridwas grown. PCT designates that the trait is calculated as a percentage.% NOT designates the percentage of plants that did not exhibit a trait.For example, STKLDG % NOT is the percentage of plants in a plot thatwere not stalk lodged. These designators will follow the descriptors todenote how the values are to be interpreted.

ABTSTK=ARTIFICIAL BRITTLE STALK. A count of the number of “snapped”plants per plot following machine snapping. A snapped plant has itsstalk completely snapped at a node between the base of the plant and thenode above the ear. Expressed as percent of plants that did not snap.

ALLELE. Any of one or more alternative forms of a genetic sequence. In adiploid cell or organism, the two alleles of a given sequence occupycorresponding loci on a pair of homologous chromosomes.

ANT ROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to 9visual rating indicating the resistance to Anthracnose Stalk Rot. Ahigher score indicates a higher resistance.

BACKCROSSING. Process in which a breeder crosses a progeny line back toone of the parental genotypes one or more times.

BARPLT=BARREN PLANTS. The percent of plants per plot that were notbarren (lack ears).

BREEDING. The genetic manipulation of living organisms.

BRTSTK=BRITTLE STALKS. This is a measure of the stalk breakage near thetime of pollination, and is an indication of whether a hybrid or inbredwould snap or break near the time of flowering under severe winds. Dataare presented as percentage of plants that did not snap.

CLDTST=COLD TEST. The percent of plants that germinate under cold testconditions.

CLN=CORN LETHAL NECROSIS. Synergistic interaction of maize chloroticmottle virus (MCMV) in combination with either maize dwarf mosaic virus(MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV). A 1 to 9 visualrating indicating the resistance to Corn Lethal Necrosis. A higher scoreindicates a higher resistance.

COMRST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicatingthe resistance to Common Rust. A higher score indicates a higherresistance.

D/D=DRYDOWN. This represents the relative rate at which a hybrid willreach acceptable harvest moisture compared to other hybrids on a 1-9rating scale. A high score indicates a hybrid that dries relatively fastwhile a low score indicates a hybrid that dries slowly.

DIPERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodiamacrospora). A 1 to 9 visual rating indicating the resistance toDiplodia Ear Mold. A higher score indicates a higher resistance.

DIPROT=DIPLODIA STALK ROT SCORE. Score of stalk rot severity due toDiplodia (Diplodia maydis). Expressed as a 1 to 9 score with 9 beinghighly resistant.

DRPEAR=DROPPED EARS. A measure of the number of dropped ears per plotand represents the percentage of plants that did not drop ears prior toharvest.

D/T=DROUGHT TOLERANCE. This represents a 1-9 rating for droughttolerance, and is based on data obtained under stress conditions. A highscore indicates good drought tolerance and a low score indicates poordrought tolerance.

EARHT=EAR HEIGHT. The ear height is a measure from the ground to thehighest placed developed ear node attachment and is measured incentimeters.

EARMLD=General Ear Mold. Visual rating (1-9 score) where a “1” is verysusceptible and a “9” is very resistant. This is based on overall ratingfor ear mold of mature ears without determining the specific moldorganism, and may not be predictive for a specific ear mold.

EARSZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

EBTSTK=EARLY BRITTLE STALK. A count of the number of “snapped” plantsper plot following severe winds when the corn plant is experiencing veryrapid vegetative growth in the V5-V8 stage. Expressed as percent ofplants that did not snap.

ECB1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinianubilalis). A 1 to 9 visual rating indicating the resistance topreflowering leaf feeding by first generation European Corn Borer. Ahigher score indicates a higher resistance.

ECB21T=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING(Ostrinia nubilalis). Average inches of tunneling per plant in thestalk.

ECB2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1to 9 visual rating indicating post flowering degree of stalk breakageand other evidence of feeding by European Corn Borer, Second Generation.A higher score indicates a higher resistance.

ECBDPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). proppedears due to European Corn Borer. Percentage of plants that did not dropears under second generation corn borer infestation.

EGR WTH=EARLY GROWTH. This is a measure of the relative height and sizeof a corn seedling at the 2-4 leaf stage of growth. This is a visualrating (1 to 9), with 1 being weak or slow growth, 5 being averagegrowth and 9 being strong growth. Taller plants, wider leaves, moregreen mass and darker color constitute higher score.

ELITE INBRED. An inbred that contributed desirable qualities when usedto produce commercial hybrids. An elite inbred may also be used infurther breeding.

ERTLDG=EARLY ROOT LODGING. Early root lodging is the percentage ofplants that do not root lodge prior to or around anthesis; plants thatlean from the vertical axis at an approximately 30° angle or greaterwould be counted as root lodged.

ERTLPN=Early root lodging. An estimate of the percentage of plants thatdo not root lodge prior to or around anthesis; plants that lean from thevertical axis at an approximately 30° angle or greater would beconsidered as root lodged.

ERTLSC=EARLY ROOT LODGING SCORE. Score for severity of plants that leanfrom a vertical axis at an approximate 30° angle or greater whichtypically results from strong winds prior to or around floweringrecorded within 2 weeks of a wind event. Expressed as a 1 to 9 scorewith 9 being no lodging.

ESTCNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on perplot basis for the inbred or hybrid.

EYESPT=Eye Spot (Kabatiella zeae or Aureobasidium zeae). A 1 to 9 visualrating indicating the resistance to Eye Spot. A higher score indicates ahigher resistance.

FUSERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusariumsubglutinans). A 1 to 9 visual rating indicating the resistance toFusarium ear rot. A higher score indicates a higher resistance.

GDU=Growing Degree Units. Using the Barger Heat Unit Theory, whichassumes that maize growth occurs in the temperature range 50° F.-86° F.and that temperatures outside this range slow down growth; the maximumdaily heat unit accumulation is 36 and the minimum daily heat unitaccumulation is 0. The seasonal accumulation of GDU is a major factor indetermining maturity zones.

GDUSHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred line or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are:

${GDU} = {\frac{\left( {{MAX}.\mspace{14mu}{temp}.{+ {{MIN}.\mspace{14mu}{temp}.}}} \right)\mspace{14mu}}{2} - 50}$

The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDUs to reach various stages of plant development.

GDUSLK=GDU TO SILK. The number of growing degree units required for aninbred line or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GENOTYPE. Refers to the genetic constitution of a cell or organism.

GIBERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9 visualrating indicating the resistance to Gibberella Ear Rot. A higher scoreindicates a higher resistance.

GIBROT=GIBBERELLA STALK ROT SCORE. Score of stalk rot severity due toGibberella (Gibberella zeae). Expressed as a 1 to 9 score with 9 beinghighly resistant.

GLFSPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1 to 9 visual ratingindicating the resistance to Gray Leaf Spot. A higher score indicates ahigher resistance.

GOSWLT=Goss' Wilt (Corynebacterium nebraskense). A 1 to 9 visual ratingindicating the resistance to Goss' Wilt. A higher score indicates ahigher resistance.

GRNAPP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain quality.

H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively high plantdensities on 1-9 relative rating system with a higher number indicatingthe hybrid responds well to high plant densities for yield relative toother hybrids. A 1, 5, and 9 would represent very poor, average, andvery good yield response, respectively, to increased plant density.

HCBLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporium carbonum).A 1 to 9 visual rating indicating the resistance to Helminthosporiuminfection. A higher score indicates a higher resistance.

HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicates thepercentage of plants not infected.

HSKCVR=HUSK COVER. A 1 to 9 score based on performance relative to keychecks, with a score of 1 indicating very short husks, tip of ear andkernels showing; 5 is intermediate coverage of the ear under mostconditions, sometimes with thin husk; and a 9 has husks extending andclosed beyond the tip of the ear. Scoring can best be done nearphysiological maturity stage or any time during dry down untilharvested.

INC D/A=GROSS INCOME (DOLLARS PER ACRE). Relative income per acreassuming drying costs of two cents per point above 15.5 percent harvestmoisture and current market price per bushel.

INCOME/ACRE. Income advantage of hybrid to be patented over other hybridon per acre basis.

INC ADV=GROSS INCOME ADVANTAGE. GROSS INCOME advantage of variety #1over variety #2.

KSZDCD=KERNEL SIZE DISCARD. The percent of discard seed; calculated asthe sum of discarded tip kernels and extra large kernels.

LINKAGE. Refers to a phenomenon wherein alleles on the same chromosometend to segregate together more often than expected by chance if theirtransmission was independent.

LINKAGE DISEQUILIBRIUM. Refers to a phenomenon wherein alleles tend toremain together in linkage groups when segregating from parents tooffspring, with a greater frequency than expected from their individualfrequencies.

UPOP=YIELD AT LOW DENSITY. Yield ability at relatively low plantdensities on a 1-9 relative system with a higher number indicating thehybrid responds well to low plant densities for yield relative to otherhybrids. A 1, 5, and 9 would represent very poor, average, and very goodyield response, respectively, to low plant density.

LRTLDG=LATE ROOT LODGING. Late root lodging is the percentage of plantsthat do not root lodge after anthesis through harvest; plants that leanfrom the vertical axis at an approximately 30° angle or greater would becounted as root lodged.

LRTLPN=LATE ROOT LODGING. Late root lodging is an estimate of thepercentage of plants that do not root lodge after anthesis throughharvest; plants that lean from the vertical axis at an approximately 30°angle or greater would be considered as root lodged.

LRTLSC=LATE ROOT LODGING SCORE. Score for severity of plants that leanfrom a vertical axis at an approximate 30° angle or greater whichtypically results from strong winds after flowering. Recorded prior toharvest when a root-lodging event has occurred. This lodging results inplants that are leaned or “lodged” over at the base of the plant and donot straighten or “goose-neck” back to a vertical position. Expressed asa 1 to 9 score with 9 being no lodging.

MDMCPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virus andMCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating theresistance to Maize Dwarf Mosaic Complex. A higher score indicates ahigher resistance.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

MSTADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 overvariety #2 as calculated by: MOISTURE of variety #2−MOISTURE of variety#1=MOISTURE ADVANTAGE of variety #1.

NLFBLT=Northern Leaf Blight (Helminthosporium turcicum or Exserohilumturcicum). A 1 to 9 visual rating indicating the resistance to NorthernLeaf Blight. A higher score indicates a higher resistance.

OILT=GRAIN OIL. Absolute value of oil content of the kernel as predictedby Near-infrared Transmittance and expressed as a percent of dry matter.

PEDIGREE DISTANCE. Relationship among generations based on theirancestral links as evidenced in pedigrees. May be measured by thedistance of the pedigree from a given starting point in the ancestry.

PLTHT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in centimeters.

POLSC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount ofpollen shed. The higher the score the more pollen shed.

POLWT=POLLEN WEIGHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage ofvariety #1 over variety #2 as calculated by PLANT POPULATION of variety#2−PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety#1.

PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relativematurity, is based on the harvest moisture of the grain. The relativematurity rating is based on a known set of checks and utilizes standardlinear regression analyses and is also referred to as the ComparativeRelative Maturity Rating System that is similar to the MinnesotaRelative Maturity Rating System.

PRMSHD=A relative measure of the growing degree units (GDU) required toreach 50% pollen shed. Relative values are predicted values from thelinear regression of observed GDU's on relative maturity of commercialchecks.

PROT=GRAIN PROTEIN. Absolute value of protein content of the kernel aspredicted by Near-infrared Transmittance and expressed as a percent ofdry matter.

RTLDG=ROOT LODGING. Root lodging is the percentage of plants that do notroot lodge; plants that lean from the vertical axis at an approximately30° angle or greater would be counted as root lodged.

RTLADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1over variety #2.

SCTGRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDGVGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A maizebreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

SLFBLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolarismaydis). A 1 to 9 visual rating indicating the resistance to SouthernLeaf Blight. A higher score indicates a higher resistance.

SOURST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual ratingindicating the resistance to Southern Rust. A higher score indicates ahigher resistance.

STAGRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STDADV=STALK STANDING ADVANTAGE. The advantage of variety #1 overvariety #2 for the trait STK CNT.

STKCNT=NUMBER OF PLANTS. This is the final stand or number of plants perplot.

STKLDG=STALK LODGING REGULAR. This is the percentage of plants that didnot stalk lodge (stalk breakage) at regular harvest (when grain moistureis between about 20 and 30%) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear.

STKLDL=LATE STALK LODGING. This is the percentage of plants that did notstalk lodge (stalk breakage) at or around late season harvest (whengrain moisture is between about 15 and 18%) as measured by eithernatural lodging or pushing the stalks and determining the percentage ofplants that break below the ear.

STKLDS=STALK LODGING SCORE. A plant is considered as stalk lodged if thestalk is broken or crimped between the ear and the ground. This can becaused by any or a combination of the following: strong winds late inthe season, disease pressure within the stalks, ECB damage orgenetically weak stalks. This trait should be taken just prior to or atharvest. Expressed on a 1 to 9 scale with 9 being no lodging.

STLPCN=STALK LODGING REGULAR. This is an estimate of the percentage ofplants that did not stalk lodge (stalk breakage) at regular harvest(when grain moisture is between about 20 and 30%) as measured by eithernatural lodging or pushing the stalks and determining the percentage ofplants that break below the ear.

STRT=GRAIN STARCH. Absolute value of starch content of the kernel aspredicted by Near-Infrared Transmittance and expressed as a percent ofdry matter.

STWWLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual ratingindicating the resistance to Stewart's Wilt. A higher score indicates ahigher resistance.

TASBLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at thetime of flowering. A 1 would indicate a very high level of blasting attime of flowering, while a 9 would have no tassel blasting.

TASSZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams)just prior to pollen shed.

TEXEAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data are given as a percentage oftillers: number of tillers per plot divided by number of plants perplot.

TSTWT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grainin pounds for a given volume (bushel).

TSWADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1over variety #2.

WIN M %=PERCENT MOISTURE WINS.

WIN Y %=PERCENT YIELD WINS.

YIELD BU/A=YIELD (BUSHELS/ACRE). Yield of the grain at harvest inbushels per acre adjusted to 15% moisture.

YLDADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety#2 as calculated by: YIELD of variety #1−YIELD variety #2=yieldadvantage of variety #1.

YLDSC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

Definitions for Area of Adaptability

When referring to area of adaptability, such term is used to describethe location with the environmental conditions that would be well suitedfor this maize line. Area of adaptability is based on a number offactors, for example: days to maturity, insect resistance, diseaseresistance, and drought resistance. Area of adaptability does notindicate that the maize line will grow in every location within the areaof adaptability or that it will not grow outside the area.

Central Corn Belt: Iowa, Illinois, Indiana

Drylands: non-irrigated areas of North Dakota, South Dakota, Nebraska,Kansas, Colorado and Oklahoma

Eastern U.S.: Ohio, Pennsylvania, Delaware, Maryland, Virginia, and WestVirginia

North central U.S.: Minnesota and Wisconsin

Northeast: Michigan, New York, Vermont, and Ontario and Quebec Canada

Northwest U.S.: North Dakota, South Dakota, Wyoming, Washington, Oregon,Montana, Utah, and Idaho

South central U.S.: Missouri, Tennessee, Kentucky, Arkansas

Southeast U.S.: North Carolina, South Carolina, Georgia, Florida,Alabama, Mississippi, and Louisiana

Southwest U.S.: Texas, Oklahoma, New Mexico, Arizona

Western U.S.: Nebraska, Kansas, Colorado, and California

Maritime Europe France, Germany, Belgium and Austria

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production ofhybrid maize lines. Inbred maize lines need to be highly homogeneous,substantially homozygous and reproducible to be useful as parents ofcommercial hybrids. There are many analytical methods available todetermine the homozygotic stability and the identity of these inbredlines.

The oldest and most traditional method of analysis is the observation ofphenotypic traits. The data is usually collected in field experimentsover the life of the maize plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with plantmorphology, ear and kernel morphology, insect and disease resistance,maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. A plant's genotype can be used to identify plants of thesame variety or a related variety. For example, the genotype can be usedto determine the pedigree of a plant. There are many laboratory-basedtechniques available for the analysis, comparison and characterizationof plant genotype; among these are Isozyme Electrophoresis, RestrictionFragment Length Polymorphisms (RFLPs), Randomly Amplified PolymorphicDNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNAAmplification Fingerprinting (DAF), Sequence Characterized AmplifiedRegions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), SimpleSequence Repeats (SSRs) which are also referred to as Microsatellites,and Single Nucleotide Polymorphisms (SNPs).

Isozyme Electrophoresis and RFLPs as discussed in Lee, M., “Inbred Linesof Maize and Their Molecular Markers,” The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432) incorporated hereinby reference, have been widely used to determine genetic composition.Isozyme Electrophoresis has a relatively low number of available markersand a low number of allelic variants among maize inbreds. RFLPs allowmore discrimination because they have a higher degree of allelicvariation in maize and a larger number of markers can be found. Both ofthese methods have been eclipsed by SSRs as discussed in Smith et al.,“An evaluation of the utility of SSR loci as molecular markers in maize(Zea mays L.): comparisons with data from RFLPs and pedigree”,Theoretical and Applied Genetics (1997) vol. 95 at 163-173 and by Pejicet al., “Comparative analysis of genetic similarity among maize inbredsdetected by RFLPs, RAPDs, SSRs, and AFLPs,” Theoretical and AppliedGenetics (1998) at 1248-1255 incorporated herein by reference. SSRtechnology is more efficient and practical to use than RFLPs; moremarker loci can be routinely used and more alleles per marker locus canbe found using SSRs in comparison to RFLPs. Single NucleotidePolymorphisms may also be used to identify the unique geneticcomposition of the invention and progeny lines retaining that uniquegenetic composition. Various molecular marker techniques may be used incombination to enhance overall resolution.

Maize DNA molecular marker linkage maps have been rapidly constructedand widely implemented in genetic studies. One such study is describedin Boppenmaier, et al., “Comparisons among strains of inbreds forRFLPs”, Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, isincorporated herein by reference.

Inbred maize line PH8DB is a yellow, dent maize inbred that is bestsuited to be used as the male in the production of first generation F1maize hybrids. Inbred maize line PH8DB is best adapted to the CentralCorn Belt, Eastern, Southcentral, and Western areas of the United Statesand can be used to produce hybrids with approximately a 110 maturitybased on the Comparative Relative Maturity Rating System for harvestmoisture of grain. Inbred maize line PH8DB demonstrates resistance toSouthern Corn Blight and common rust, and moderate resistance to GrayLeaf Spot as an inbred per se. In hybrid combination inbred PH8DBdemonstrates high yield and grain test weight, good early standestablishment and early growth, low ear height, good late season rootstrength, resistance to Gray Leaf Spot and common rust, and droughttolerance.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1) that follows. The inbred has beenself-pollinated and ear-rowed a sufficient number of generations withcareful attention paid to uniformity of plant type to ensure thehomozygosity and phenotypic stability necessary to use in commercialproduction. The line has been increased both by hand and in isolatedfields with continued observation for uniformity. No variant traits havebeen observed or are expected in PH8DB.

Inbred maize line PH8DB, being substantially homozygous, can bereproduced by planting seeds of the line, growing the resulting maizeplants under self-pollinating or sib-pollinating conditions withadequate isolation, and harvesting the resulting seed using techniquesfamiliar to the agricultural arts.

TABLE 1 VARIETY DESCRIPTION INFORMATION VARIETY = PH8DB 1. TYPE:(describe intermediate types in Comments section): 2 1=Sweet 2=Dent3=Flint 4=Flour 5=Pop 6=Ornamental 2. MATURITY: DAYS HEAT UNITS 0711,452.7 From emergence to 50% of plants in silk 069 1,412.3 Fromemergence to 50% of plants in pollen 002 0,066.0 From 10% to 90% pollenshed From 50% silk to harvest at 25% moisture Standard Sample 3. PLANT:Deviation Size 212.3 cm Plant Height (to tassel tip) 20.98 15 72.7 cmEar Height (to base of top ear node) 6.81 15 15.3 cm Length of Top EarInternode 1.90 15 0.3 Average Number of Tillers per plant 0.26 3 0.9Average Number of Ears per Stalk 0.01 3 3.0 Anthocyanin of Brace Roots:1 = Absent 2 = Faint 3 = Moderate 4 = Dark 5 = Very Dark Standard Sample4. LEAF: Deviation Size 10.6 cm Width of Ear Node Leaf 0.53 15 85.6 cmLength of Ear Node Leaf 2.96 15 06.3 Number of leaves above top ear 0.9215 022.1 Degrees Leaf Angle (measure from 2nd leaf 4.42 15 above ear atanthesis to stalk above leaf) 15 03 Leaf Color  Dark Green  (Munsellcode)  7.5GY34 1.7 Leaf Sheath Pubescence (Rate on scale from 1=none to9=like peach fuzz) Marginal Waves (Rate on scale from 1 =none to 9=many)Longitudinal Creases (Rate on scale from 1 =none to 9=many) StandardSample 5. TASSEL: Deviation Size 09.3 Number of Primary Lateral Branches0.31 15 023.1 Branch Angle from Central Spike 3.43 15 63.5 cm TasselLength (from top leaf collar to tassel tip) 2.14 15 6.3 Pollen Shed(rate on scale from 0=male sterile to 9=heavy shed) 01 Anther Color Light Green  (Munsell code)  10Y88 01 Glume Color  Light Green (Munsell code)  7.5GY34 1.0 Bar Glumes (Glume Bands): 1 =Absent2=Present 25 cm Peduncle Length (cm. from top leaf to basal branches 6a.EAR (Unhusked Data): 1 Silk Color (3 days after emergence)  Light Green(Munsell code) 2.5GY86 1 Fresh Husk Color (25 days after 50% silking) Light Green (Munsell code) 5GY68 21 Dry Husk Color (65 days after 50%silking)  Buff (Munsell code) 5Y91 1 Position of Ear at Dry Husk Stage:1=Upright 2=Horizontal 3=Pendant Upright 4 Husk Tightness (Rate of Scalefrom 1=very loose to 9=very tight) 2 Husk Extension (at harvest):1=Short (ears exposed) 2=Medium (<8 cm) 3=Long (8-10 cm beyond ear tip)4=Very Long (>10 cm) 6b. EAR (Husked Ear Data): Standard SampleDeviation Size 17 cm Ear Length 1.53 15 44 mm Ear Diameter at mid-point2.52 15 144 gm Ear Weight 32.6 15 18 Number of Kernel Rows 0.58 15 2Kernel Rows: 1=Indistinct 2=Distinct 2 Row Alignment: 1=Straight2=Slightly Curved 3=Spiral 9 cm Shank Length 1.53 15 2 Ear Taper:1=Slight 2=Average 3=Extreme Standard Sample 7. KERNEL (Dried):Deviation Size 11 mm Kernel Length 0.58 15 7 mm Kernel Width 0.58 15 5mm Kernel Thickness 0.00 15 40 % Round Kernels (Shape Grade) 9.07 3 1Aleurone Color Pattern: 1=Homozygous 2=Segregating 7 Aluerone ColorYellow  (Munsell code) 1.25Y816 7 Hard Endosperm Color  Yellow  (Munsellcode) 1.25Y814 3 Endosperm Type:  Normal Starch 1=Sweet (Su1) 2=ExtraSweet (sh2) 3=Normal Starch 4=High Amylose Starch 5=Waxy Starch 6=HighProtein 7=High Lysine 8=Super Sweet (se) 9=High Oil 10=Other 27 gmWeight per 100 Kernels (unsized sample) 1.53 3 Standard Sample 8. COB:Deviation Size 24 mm Cob Diameter at mid-point 1.15 15 11 Cob Color Pink  (Munsell code) 10R6 9. DISEASE RESISTANCE (Rate from 1 (mostsusceptible) to 9 (most resistant); leave blank if not tested; leaveRace or Strain Options blank if polygenic): A. Leaf Blights, Wilts, andLocal Infection Diseases Anthracnose Leaf Blight (Colletotrichumgraminicola) 6 Common Rust (Puccinia sorghi) Common Smut (Ustilagomaydis) Eyespot (Kabatiella zeae) Goss's Wilt (Clavibacter michiganensespp. nebraskense) 6 Gray Leaf Spot (Cercospora zeae-maydis)Helminthosporium Leaf Spot (Bipolaris zeicola) Race 6 Northern LeafBlight (Exserohilum turcicum) Race 7 Southern Leaf Blight (Bipolarismaydis) Race Southern Rust (Puccinia polysora) 6 Stewart's Wilt (Erwiniastewartii) Other (Specify)------ B. Systemic Diseases Corn LethalNecrosis (MCMV and MDMV) Head Smut (Sphacelotheca reiliana) MaizeChlorotic Dwarf Virus (MDV) Maize Chlorotic Mottle Virus (MCMV) MaizeDwarf Mosaic Virus (MDMV) Sorghum Downy Mildew of Corn(Peronosclerospora sorghi) Other (Specify)----- C. Stalk Rots 4Anthracnose Stalk Rot (Colletotrichum graminicola) Diplodia Stalk Rot(Stenocarpella maydis) Fusarium Stalk Rot (Fusarium moniliforme)Gibberella Stalk Rot (Gibberella zeae) Other (Specify)----- D. Ear andKernel Rots Aspergillus Ear and Kernel Rot (Aspergillus flavus) 6Diplodia Ear Rot (Stenocarpella maydis) 6 Fusarium Ear and Kernel Rot(Fusarium moniliforme) 9 Gibberella Ear Rot (Gibberella zeae) Other(Specify)----- 10. INSECT RESISTANCE (Rate from 1 (most susceptible) to9 (most resistant); (leave blank if not tested) Banks grass Mite(Oligonychus pratensis) Corn Worm (Helicoverpa zea) Leaf Feeding SilkFeeding mg larval wt. Ear Damage Corn Leaf Aphid (Rhopalosiphum maidis)Corn Sap Beetle (Carpophilus dimidiatus European Corn Borer (Ostrinianubilalis) 1st Generation (Typically Whorl Leaf Feeding) 2nd Generation(Typically Leaf Sheath-Collar Feeding) Stalk Tunneling cm tunneled/plantFall Armyworm (Spodoptera fruqiperda) Leaf Feeding Silk Feeding mglarval wt. Maize Weevil (Sitophilus zeamaize) Northern Rootworm(Diabrotica barberi) Southern Rootworm (Diabrotica undecimpunctata)Southwestern Corn Borer (Diatreaea grandiosella) Leaf Feeding StalkTunneling cm tunneled/plant Two-spotted Spider Mite (Tetranychusurticae) Western Rootworm (Diabrotica virgifrea virgifera) Other(Specify)----- 11. AGRONOMIC TRAITS: 5 Staygreen (65 days afteranthesis. Rate on a scale from 1=worst to 9=excellent) 0.0 % DroppedEars (at 65 days after anthesis) % Pre-anthesis Brittle Snapping %Pre-anthesis Root Lodging 0.0 Post-anthesis Root Lodging (at 65 daysafter anthesis) 7,197 Kg/ha Yield (at 12-13% grain moisture)

FURTHER EMBODIMENTS OF THE INVENTION

This invention also is directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein either the first or second parent maize plant is an inbred maizeplant of the line PH8DB. Further, both first and second parent maizeplants can come from the inbred maize line PH8DB. Still further, thisinvention also is directed to methods for producing an inbred maize linePH8DB-derived maize plant by crossing inbred maize line PH8DB with asecond maize plant and growing the progeny seed, and repeating thecrossing and growing steps with the inbred maize line PH8DB-derivedplant from 1 to 2 times, 1 to 3 times 1 to 4 times, or 1 to 5 times.Thus, any such methods using the inbred maize line PH8DB are part ofthis invention: selfing, sibbing, backcrosses, hybrid production,crosses to populations, and the like. All plants produced using inbredmaize line PH8DB as a parent are within the scope of this invention,including plants derived from inbred maize line PH8DB. This includesvarieties essentially derived from variety PH8DB with the term“essentially derived variety” having the meaning ascribed to such termin 7 U.S.C. § 2104(a)(3) of the Plant Variety Protection Act, whichdefinition is hereby incorporated by reference. This also includesprogeny plants and parts thereof with at least one ancestor that isPH8DB, and more specifically, where the pedigree of the progeny includes1, 2, 3, 4, and/or 5 or less cross-pollinations to a maize plant otherthan PH8DB or a plant that has PH8DB as a progenitor. All breeders ofordinary skill in the art maintain pedigree records of their breedingprograms. These pedigree records contain a detailed description of thebreeding process, including a listing of all parental lines used in thebreeding process and information on how such line was used. Thus, abreeder would know if PH8DB were used in the development of a progenyline, and would also know how many crosses to a line other than PH8DB orline with PH8DB as a progenitor were made in the development of anyprogeny line. The inbred maize line may also be used in crosses withother, different, maize inbreds to produce first generation (F₁) maizehybrid seeds and plants with superior characteristics.

Specific methods and products produced using inbred line PH8DB in plantbreeding are encompassed within the scope of the invention listed above.

One such embodiment is a method for developing a PH8DB progeny maizeplant in a maize plant breeding program comprising: obtaining PH8DB orits parts, utilizing said plant or plant parts as a source of breedingmaterial; and selecting a PH8DB progeny plant with molecular markers incommon with PH8DB or morphological and/or physiological characteristicsselected from the characteristics listed in Tables 1 or 2. Breedingsteps that may be used in the maize plant breeding program includepedigree breeding, backcrossing, mutation breeding, and recurrentselection. In conjunction with these steps, techniques such asrestriction fragment polymorphism enhanced selection, genetic markerenhanced selection (for example SSR markers), and the making of doublehaploids may be utilized.

Another such embodiment is the method of crossing inbred maize linePH8DB with another maize plant, such as a different maize inbred line,to form a first generation population of F1 hybrid plants. Thepopulation of first generation F1 hybrid plants produced by this methodis also an embodiment of the invention. This first generation populationof F1 plants will comprise an essentially complete set of the alleles ofinbred line PH8DB. One of ordinary skill in the art can utilize eitherbreeder books or molecular methods to identify a particular F1 hybridplant produced using inbred line PH8DB, and any such individual plant isalso encompassed by this invention. These embodiments also cover use ofthese methods with transgenic or single gene conversions of inbred linePH8DB.

Another such embodiment of this invention is a method of using inbredline PH8DB in breeding that involves the repeated backcrossing to inbredline PH8DB any number of times. Using backcrossing methods, or even thetissue culture and transgenic methods described herein, the single geneconversion methods described herein, or other breeding methods known toone of ordinary skill in the art, one can develop individual plants,plant cells, and populations of plants that retain at least 25%, 30%,35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%,84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, 99% or 99.5% genetic contribution from inbred line PH8DB. Thepercentage of the genetics retained in the progeny may be measured byeither pedigree analysis or through the use of genetic techniques suchas molecular markers or electrophoresis. In pedigree analysis, onaverage 50% of the starting germplasm would be passed to the progenyline after one cross to another line, 25% after another cross to adifferent line, and so on. Molecular markers could also be used toconfirm and/or determine the pedigree of the progeny line.

One method for producing a line derived from inbred line PH8DB is asfollows. One of ordinary skill in the art would obtain a seed from thecross between inbred line PH8DB and another variety of maize, such as anelite inbred variety. The F1 seed derived from this cross would be grownto form a homogeneous population. The F1 seed would contain essentiallyall of the alleles from variety PH8DB and essentially all of the allelesfrom the other maize variety. The F1 nuclear genome would be made-up of50% variety PH8DB and 50% of the other elite variety. The F1 seed wouldbe grown and allowed to self, thereby forming F2 seed. On average the F2seed would have derived 50% of its alleles from variety PH8DB and 50%from the other maize variety, but many individual plants from thepopulation would have a greater percentage of their alleles derived fromPH8DB (Wang J. and R. Bernardo, 2000, Crop Sci. 40:659-665 and Bernardo,R. and A. L. Kahler, 2001, Theor. Appl. Genet 102:986-992). Themolecular markers of PH8DB could be used to select and retain thoselines with high similarity to PH8DB. The F2 seed would be grown andselection of plants would be made based on visual observation, markersand/or measurement of traits. The traits used for selection may be anyPH8DB trait described in this specification, including the inbred maizePH8DB traits of comparably good resistance to Southern corn Blight,common rust, and Grey Leaf Spot. Such traits may also be the goodgeneral or specific combining ability of PH8DB, including its ability toproduce hybrids with an approximate 110 CRM maturity, comparably highyield, comparably good grain test weight, comparably good early standestablishment and early growth, comparably good low ear height,comparably good late season root strength, comparably good resistance toGrey Leaf spot and common rust, and comparably good drought tolerance.The PH8DB progeny plants that exhibit one or more of the desired PH8DBtraits, such as those listed above, would be selected and each plantwould be harvested separately. This F3 seed from each plant would begrown in individual rows and allowed to self. Then selected rows orplants from the rows would be harvested individually. The selectionswould again be based on visual observation, markers and/or measurementsfor desirable traits of the plants, such as one or more of the desirablePH8DB traits listed above. The process of growing and selection would berepeated any number of times until a PH8DB progeny inbred plant isobtained. The PH8DB progeny inbred plant would contain desirable traitsderived from inbred plant PH8DB, some of which may not have beenexpressed by the other maize variety to which inbred line PH8DB wascrossed and some of which may have been expressed by both maizevarieties but now would be at a level equal to or greater than the levelexpressed in inbred variety PH8DB. However, in each case the resultingprogeny line would benefit from the efforts of the inventor(s), andwould not have existed but for the inventor(s) work in creating PH8DB.The PH8DB progeny inbred plants would have, on average, 50% of theirnuclear genes derived from inbred line PH8DB, but many individual plantsfrom the population would have a greater percentage of their allelesderived from PH8DB. This breeding cycle, of crossing and selfing, andoptional selection, may be repeated to produce another population ofPH8DB progeny maize plants with, on average, 25% of their nuclear genesderived from inbred line PH8DB, but, again, many individual plants fromthe population would have a greater percentage of their alleles derivedfrom PH8DB. Another embodiment of the invention is a PH8DB progeny plantthat has received the desirable PH8DB traits listed above through theuse of PH8DB, which traits were not exhibited by other plants used inthe breeding process.

The previous example can be modified in numerous ways, for instanceselection may or may not occur at every selfing generation, selectionmay occur before or after the actual self-pollination process occurs, orindividual selections may be made by harvesting individual ears, plants,rows or plots at any point during the breeding process described. Inaddition, double haploid breeding methods may be used at any step in theprocess. The population of plants produced at each and any cycle ofbreeding is also an embodiment of the invention, and on average eachsuch population would predictably consist of plants containingapproximately 50% of its genes from inbred line PH8DB in the firstbreeding cycle, 25% of its genes from inbred line PH8DB in the secondbreeding cycle, 12.5% of its genes from inbred line PH8DB in the thirdbreeding cycle and so on. However, in each case the use of PH8DBprovides a substantial benefit. The linkage groups of PH8DB would beretained in the progeny lines, and since current estimates of the maizegenome size is about 50,000-80,000 genes (Xiaowu, Gai et al., NucleicAcids Research, 2000, Vol. 28, No. 1, 94-96), in addition to non-codingDNA that impacts gene expression, it provides a significant advantage touse PH8DB as starting material to produce a line that retains desiredgenetics or traits of PH8DB.

Another embodiment of this invention is the method of obtaining asubstantially homozygous PH8DB progeny plant by obtaining a seed fromthe cross of PH8DB and another maize plant and applying double haploidmethods to the F1 seed or F1 plant or to any successive filialgeneration. Such methods decrease the number of generations required toproduce an inbred with similar genetics or characteristics to PH8DB. SeeBernardo, R. and Kahler, A. L., Theor. Appl. Genet. 102:986-992, 2001.

A further embodiment of the invention is a single gene conversion ofPH8DB. A single gene conversion occurs when DNA sequences are introducedthrough traditional (non-transformation) breeding techniques, such asbackcrossing (Hallauer et al., 1988). DNA sequences, whether naturallyoccurring or transgenes, may be introduced using these traditionalbreeding techniques. The term single gene conversion is also referred toin the art as a single locus conversion. Reference is made to US2002/0062506A1 for a detailed discussion of single locus conversions andtraits that may be incorporated into PH8DB through single geneconversion. Desired traits transferred through this process include, butare not limited to, waxy starch, nutritional enhancements, industrialenhancements, disease resistance, insect resistance, herbicideresistance and yield enhancements. The trait of interest is transferredfrom the donor parent to the recurrent parent, in this case, the maizeplant disclosed herein. Single gene traits may result from either thetransfer of a dominant allele or a recessive allele. Selection ofprogeny containing the trait of interest is accomplished by directselection for a trait associated with a dominant allele. Selection ofprogeny for a trait that is transferred via a recessive allele, such asthe waxy starch characteristic, requires growing and selfing the firstbackcross generation to determine which plants carry the recessivealleles. Recessive traits may require additional progeny testing insuccessive backcross generations to determine the presence of the geneof interest. Along with selection for the trait of interest, progeny areselected for the phenotype of the recurrent parent. It should beunderstood that occasionally additional polynucleotide sequences orgenes are transferred along with the single gene conversion trait ofinterest. A progeny comprising at least 98%, 99%, 99.5% and 99.9% of thegenes from the recurrent parent, the maize line disclosed herein, pluscontaining the single gene conversion trait or traits of interest, isconsidered to be a single gene conversion of inbred line PH8DB.

It should be understood that the inbred can, through routinemanipulation by detasseling, cytoplasmic genes, nuclear genes, or otherfactors, be produced in a male-sterile form. Such embodiments are alsowithin the scope of the present claims. The term manipulated to be malesterile refers to the use of any available techniques to produce a malesterile version of maize line PH8DB. The male sterility may be eitherpartial or complete male sterility.

This invention is also directed to the use of PH8DB in tissue culture.As used herein, the term plant includes plant protoplasts, plant celltissue cultures from which maize plants can be regenerated, plant calli,plant clumps, and plant cells that are intact in plants or parts ofplants, such as embryos, pollen, ovules, seeds, flowers, kernels, ears,cobs, leaves, husks, stalks, roots, root tips, anthers, silk and thelike. As used herein, phrases such as “growing the seed” or “grown fromthe seed” include embryo rescue, isolation of cells from seed for use intissue culture, as well as traditional growing methods.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322-332 reflectsthat 97% of the plants cultured that produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus that produced plants. In a further studyin 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions that enhance regenerability ofcallus of two inbred lines. Other published reports also indicated that“nontraditional” tissues are capable of producing somatic embryogenesisand plant regeneration. K. P. Rao, et al., Maize Genetics CooperationNewsletter, 60:64-65 (1986), refers to somatic embryogenesis from glumecallus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347(1987) indicates somatic embryogenesis from the tissue cultures of maizeleaf segments. Thus, it is clear from the literature that the state ofthe art is such that these methods of obtaining plants are, and were,“conventional” in the sense that they are routinely used and have a veryhigh rate of success.

Tissue culture of maize, including tassel/anther culture, is describedin U.S. Publication No. 2002/0062506A1 and European Patent Application,Publication No. 160,390, each of which are incorporated herein byreference. Maize tissue culture procedures are also described in Greenand Rhodes, “Plant Regeneration in Tissue Culture of Maize,” Maize forBiological Research (Plant Molecular Biology Association,Charlottesville, Va. 1982, at 367-372) and in Duncan, et al., “TheProduction of Callus Capable of Plant Regeneration from Immature Embryosof Numerous Zea Mays Genotypes,” 165 Planta 322-332 (1985). Thus,another aspect of this invention is to provide cells which upon growthand differentiation produce maize plants having the genotype and/orphysiological and morphological characteristics of inbred line PH8DB.

The utility of inbred maize line PH8DB also extends to crosses withother species. Commonly, suitable species will be of the familyGraminaceae, and especially of the genera Zea, Tripsacum, Coix,Schlerachne, Polytoca, Chionachne, and Trilobachne, of the tribeMaydeae. Potentially suitable for crosses with PH8DB may be the variousvarieties of grain sorghum, Sorghum bicolor (L.) Moench.

The advent of new molecular biological techniques has allowed theisolation and characterization of genetic elements with specificfunctions, such as encoding specific protein products. Scientists in thefield of plant biology developed a strong interest in engineering thegenome of plants to contain and express foreign genetic elements, oradditional, or modified versions of native or endogenous geneticelements in order to alter the traits of a plant in a specific manner.Any DNA sequences, whether from a different species or from the samespecies, that are inserted into the genome using transformation arereferred to herein collectively as “transgenes”. Over the last fifteento twenty years several methods for producing transgenic plants havebeen developed, and the present invention, in particular embodiments,also relates to transformed versions of the claimed inbred maize linePH8DB.

Numerous methods for plant transformation have been developed, includingbiological and physical, plant transformation protocols. See, forexample, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages67-88 and Armstrong, “The First Decade of Maize Transformation: A Reviewand Future Perspective” (Maydica 44:101-109, 1999). In addition,expression vectors and in vitro culture methods for plant cell or tissuetransformation and regeneration of plants are available. See, forexample, Gruber et al., “Vectors for Plant Transformation” in Methods inPlant Molecular Biology and Biotechnology, Glick, B. R. and Thompson, J.E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages 89-119. See U.S. Pat.No. 6,118,055, which is herein incorporated by reference.

The most prevalent types of plant transformation involve theconstruction of an expression vector. Such a vector comprises a DNAsequence that contains a gene under the control of or operatively linkedto a regulatory element, for example a promoter. The vector may containone or more genes and one or more regulatory elements.

A genetic trait which has been engineered into a particular maize plantusing transformation techniques, could be moved into another line usingtraditional breeding techniques that are well known in the plantbreeding arts. For example, a backcrossing approach could be used tomove a transgene from a transformed maize plant to an elite inbred lineand the resulting progeny would comprise a transgene. Also, if an inbredline was used for the transformation then the transgenic plants could becrossed to a different inbred in order to produce a transgenic hybridmaize plant. As used herein, “crossing” can refer to a simple X by Ycross, or the process of backcrossing, depending on the context.

Various genetic elements can be introduced into the plant genome usingtransformation. These elements include but are not limited to genes;coding sequences; inducible, constitutive, and tissue specificpromoters; enhancing sequences; and signal and targeting sequences. SeeU.S. Pat. No. 6,118,055, which is herein incorporated by reference.

With transgenic plants according to the present invention, a foreignprotein can be produced in commercial quantities. Thus, techniques forthe selection and propagation of transformed plants, which are wellunderstood in the art, yield a plurality of transgenic plants which areharvested in a conventional manner, and a foreign protein then can beextracted from a tissue of interest or from total biomass. Proteinextraction from plant biomass can be accomplished by known methods whichare discussed, for example, by Heney and Orr, Anal. Biochem. 114: 92-6(1981).

According to a preferred embodiment, the transgenic plant provided forcommercial production of foreign protein is maize. In another preferredembodiment, the biomass of interest is seed. A genetic map can begenerated, primarily via conventional Restriction Fragment LengthPolymorphisms (RFLP), Polymerase Chain Reaction (PCR) analysis, andSimple Sequence Repeats (SSR) and Single Nucleotide Polymorphisms (SNP)which identifies the approximate chromosomal location of the integratedDNA molecule. For exemplary methodologies in this regard, see Glick andThompson, METHODS IN PLANT MOLECULAR BIOLOGY AND BIOTECHNOLOGY 269-284(CRC Press, Boca Raton, 1993). Wang et al. discuss “Large ScaleIdentification, Mapping and Genotyping of Single-NucleotidePolymorphorsms in the Human Genome”, Science, 280:1077-1082, 1998, andsimilar capabilities will soon be available for the corn genome. Mapinformation concerning chromosomal location is useful for proprietaryprotection of a subject transgenic plant. If unauthorized propagation isundertaken and crosses made with other germplasm, the map of theintegration region can be compared to similar maps for suspect plants,to determine if the latter have a common parentage with the subjectplant. Map comparisons would involve hybridizations, RFLP, PCR, SSR andsequencing, all of which are conventional techniques. SNP's may also beused alone or in combination with other techniques.

Likewise, by means of the present invention, plants can be geneticallyengineered to express various phenotypes of agronomic interest. Throughthe transformation of maize the expression of genes can be modulated toenhance disease resistance, insect resistance, herbicide resistance,agronomic traits as well as grain quality traits. Transformation canalso be used to insert DNA sequences which control or help controlmale-sterility. DNA sequences native to maize as well as non-native DNAsequences can be transformed into maize and used to modulate levels ofnative or non-native proteins. Anti-sense technology, various promoters,targeting sequences, enhancing sequences, and other DNA sequences can beinserted into the maize genome for the purpose of modulating theexpression of proteins. Exemplary transgenes implicated in this regardinclude, but are not limited to, those categorized below.

1. Transgenes that Confer Resistance to Pests or Disease and thatEncode:

(A) Plant disease resistance genes. Plant defenses are often activatedby specific interaction between the product of a disease resistance gene(R) in the plant and the product of a corresponding avirulence (Avr)gene in the pathogen. A plant variety can be transformed with clonedresistance gene to engineer plants that are resistant to specificpathogen strains. See, for example Jones et al., Science 266: 789 (1994)(cloning of the tomato Cf-9 gene for resistance to Cladosporium fulvum);Martin et al., Science 262: 1432 (1993) (tomato Pto gene for resistanceto Pseudomonas syringae pv. tomato encodes a protein kinase); Mindrinoset al., Cell 78: 1089 (1994) (Arabidopsis RSP2 gene for resistance toPseudomonas syringae).

(B) A Bacillus thuringiensis protein, a derivative thereof or asynthetic polypeptide modeled thereon. See, for example, Geiser et al.,Gene 48: 109 (1986), who disclose the cloning and nucleotide sequence ofa Bt δ-endotoxin gene. Moreover, DNA molecules encoding δ-endotoxingenes can be purchased from American Type Culture Collection (Rockville,Md.), for example, under ATCC Accession Nos. 40098, 67136, 31995 and31998. Other examples of Bacillus thuringiensis trangenes beinggenetically engineered are given in the following patents and hereby areincorporated by reference: U.S. Pat. Nos. 5,188,960; 5,689,052;5,880,275; and WO 97/40162.

(C) A lectin. See, for example, the disclosure by Van Damme et al.,Plant Molec. Biol. 24: 25 (1994), who disclose the nucleotide sequencesof several Clivia miniata mannose-binding lectin genes.

(D) A vitamin-binding protein such as avidin. See PCT Application No.US93/06487 the contents of which are hereby incorporated by reference.The application teaches the use of avidin and avidin homologues aslarvicides against insect pests.

(E) An enzyme inhibitor, for example, a protease inhibitor or an amylaseinhibitor. See, for example, Abe et al., J. Biol. Chem. 262: 16793(1987) (nucleotide sequence of rice cysteine proteinase inhibitor), Huubet al., Plant Molec. Biol. 21: 985 (1993) (nucleotide sequence of cDNAencoding tobacco proteinase inhibitor I), and Sumitani et al., Biosci.Biotech. Biochem. 57: 1243 (1993) (nucleotide sequence of Streptomycesnitrosporeus α-amylase inhibitor) and U.S. Pat. No. 5,494,813.

(F) An insect-specific hormone or pheromone such as an ecdysteroid andjuvenile hormone, a variant thereof, a mimetic based thereon, or anantagonist or agonist thereof. See, for example, the disclosure byHammock et al., Nature 344: 458 (1990), of baculovirus expression ofcloned juvenile hormone esterase, an inactivator of juvenile hormone.

(G) An insect-specific peptide or neuropeptide which, upon expression,disrupts the physiology of the affected pest. For example, see thedisclosures of Regan, J. Biol. Chem. 269: 9 (1994) (expression cloningyields DNA coding for insect diuretic hormone receptor), and Pratt etal., Biochem. Biophys. Res. Comm. 163: 1243 (1989) (an allostatin isidentified in Diploptera puntata). See also U.S. Pat. No. 5,266,317 toTomalski et al., who disclose genes encoding insect-specific, paralyticneurotoxins.

(H) An insect-specific venom produced in nature by a snake, a wasp, etc.For example, see Pang et al., Gene 116: 165 (1992), for disclosure ofheterologous expression in plants of a gene coding for a scorpioninsectotoxic peptide.

(I) An enzyme responsible for an hyperaccumulation of a monterpene, asesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid derivativeor another non-protein molecule with insecticidal activity.

(J) An enzyme involved in the modification, including thepost-translational modification, of a biologically active molecule; forexample, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme,a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, aphosphatase, a kinase, a phosphorylase, a polymerase, an elastase, achitinase and a glucanase, whether natural or synthetic. See PCTApplication No. WO 93/02197 in the name of Scott et al., which disclosesthe nucleotide sequence of a callase gene. DNA molecules which containchitinase-encoding sequences can be obtained, for example, from the ATCCunder Accession Nos. 39637 and 67152. See also Kramer et al., InsectBiochem. Molec. Biol. 23: 691 (1993), who teach the nucleotide sequenceof a cDNA encoding tobacco hookworm chitinase, and Kawalleck et al.,Plant Molec. Biol. 21: 673 (1993), who provide the nucleotide sequenceof the parsley ubi4-2 polyubiquitin gene.

(K) A molecule that stimulates signal transduction. For example, see thedisclosure by Botella et al., Plant Molec. Biol. 24: 757 (1994), ofnucleotide sequences for mung bean calmodulin cDNA clones, and Griess etal., Plant Physiol. 104: 1467 (1994), who provide the nucleotidesequence of a maize calmodulin cDNA clone.

(L) A hydrophobic moment peptide. See PCT Application No. WO95/16776(disclosure of peptide derivatives of Tachyplesin which inhibit fungalplant pathogens) and PCT Application No. WO95/18855 (teaches syntheticantimicrobial peptides that confer disease resistance), the respectivecontents of which are hereby incorporated by reference.

(M) A membrane permease, a channel former or a channel blocker. Forexample, see the disclosure by Jaynes et al., Plant Sci. 89: 43 (1993),of heterologous expression of a cecropin-β lytic peptide analog torender transgenic tobacco plants resistant to Pseudomonas solanacearum.

(N) A viral-invasive protein or a complex toxin derived therefrom. Forexample, the accumulation of viral coat proteins in transformed plantcells imparts resistance to viral infection and/or disease developmenteffected by the virus from which the coat protein gene is derived, aswell as by related viruses. See Beachy et al., Ann. Rev. Phytopathol.28: 451 (1990). Coat protein-mediated resistance has been conferred upontransformed plants against alfalfa mosaic virus, cucumber mosaic virus,tobacco streak virus, potato virus X, potato virus Y, tobacco etchvirus, tobacco rattle virus and tobacco mosaic virus. Id.

(O) An insect-specific antibody or an immunotoxin derived therefrom.Thus, an antibody targeted to a critical metabolic function in theinsect gut would inactivate an affected enzyme, killing the insect. Cf.Taylor et al., Abstract #497, SEVENTH INT'L SYMPOSIUM ON MOLECULARPLANT-MICROBE INTERACTIONS (Edinburgh, Scotland, 1994) (enzymaticinactivation in transgenic tobacco via production of single-chainantibody fragments).

(P) A virus-specific antibody. See, for example, Tavladoraki et al.,Nature 366: 469 (1993), who show that transgenic plants expressingrecombinant antibody genes are protected from virus attack.

(Q) A developmental-arrestive protein produced in nature by a pathogenor a parasite. Thus, fungal endo α-1,4-D-polygalacturonases facilitatefungal colonization and plant nutrient release by solubilizing plantcell wall homo-α-1,4-D-galacturonase. See Lamb et al., Bio/Technology10: 1436 (1992). The cloning and characterization of a gene whichencodes a bean endopolygalacturonase-inhibiting protein is described byToubart et al., Plant J. 2: 367 (1992).

(R) A developmental-arrestive protein produced in nature by a plant. Forexample, Logemann et al., Bio/Technology 10: 305 (1992), have shown thattransgenic plants expressing the barley ribosome-inactivating gene havean increased resistance to fungal disease.

(S) Genes involved in the Systemic Acquired Resistance (SAR) Responseand/or the pathogenesis related genes. Briggs, S., Current Biology, 5(2)(1995).

(T) Antifungal genes (Cornelissen and Melchers, P I. Physiol.101:709-712, (1993) and Parijs et al., Planta 183:258-264, (1991) andBushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998).

2. Transgenes that Confer Resistance to a Herbicide, for Example:

(A) A herbicide that inhibits the growing point or meristem, such as animidazolinone or a sulfonylurea. Exemplary genes in this category codefor mutant ALS and AHAS enzyme as described, for example, by Lee et al.,EMBO J. 7: 1241 (1988), and Miki et al., Theor. Appl. Genet. 80: 449(1990), respectively. See also, U.S. Pat. Nos. 5,605,011; 5,013,659;5,141,870; 5,767,361; 5,731,180; 5,304,732; 4,761,373; 5,331,107;5,928,937; and 5,378,824; and international Publication No. WO 96/33270,which are incorporated herein by reference in their entireties for allpurposes.

(B) Glyphosate (resistance imparted by mutant5-enolpyruvl-3-phosphikimate synthase (EPSP) and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase (PAT) and Streptomyceshygroscopicus phosphinothricin acetyl transferase (bar) genes), andpyridinoxy or phenoxy proprionic acids and cycloshexones (ACCaseinhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 toShah et al., which discloses the nucleotide sequence of a form of EPSPSwhich can confer glyphosate resistance. U.S. Pat. No. 5,627,061 to Barryet al. also describes genes encoding EPSPS enzymes. See also U.S. Pat.Nos. 6,248,876 B1; 6,040,497; 5,804,425; 5,633,435; 5,145,783;4,971,908; 5,312,910; 5,188,642; 4,940,835; 5,866,775; 6,225,114 B1;6,130,366; 5,310,667; 4,535,060; 4,769,061; 5,633,448; 5,510,471; Re.36,449; RE 37,287 E; and 5,491,288; and international Publication Nos.WO 97/04103; WO 97/04114; WO 00/66746; WO 01/66704; WO 00/66747 and WO00/66748, which are incorporated herein by reference in their entirety.Glyphosate resistance is also imparted to plants that express a genethat encodes a glyphosate oxido-reductase enzyme as described more fullyin U.S. Pat. Nos. 5,776,760 and 5,463,175, which are incorporated hereinby reference in their entirety. In addition glyphosate resistance can beimparted to plants by the over expression of genes encoding glyphosateN-acetyltransferase. See, for example, U.S. Application Ser. Nos.60/244,385; 60/377,175 and 60/377,719.

A DNA molecule encoding a mutant aroA gene can be obtained under ATCCAccession No. 39256, and the nucleotide sequence of the mutant gene isdisclosed in U.S. Pat. No. 4,769,061 to Comai. European PatentApplication No. 0 333 033 to Kumada et al. and U.S. Pat. No. 4,975,374to Goodman et al. disclose nucleotide sequences of glutamine synthetasegenes which confer resistance to herbicides such as L-phosphinothricin.The nucleotide sequence of a phosphinothricin-acetyl-transferase gene isprovided in European Patent No. 0 242 246 and 0 242 236 to Leemans etal. De Greef et al., Bio/Technology 7:61 (1989), describe the productionof transgenic plants that express chimeric bar genes coding forphosphinothricin acetyl transferase activity. See also, U.S. Pat. Nos.5,969,213; 5,489,520; 5,550,318; 5,874,265; 5,919,675; 5,561,236;5,648,477; 5,646,024; 6,177,616 B1; and 5,879,903, which areincorporated herein by reference in their entirety. Exemplary of genesconferring resistance to phenoxy proprionic acids and cycloshexones,such as sethoxydim and haloxyfop, are the Acc1-S1, Acc1-S2 and Acc1-S3genes described by Marshall et al., Theor. Appl. Genet. 83: 435 (1992).

(C) A herbicide that inhibits photosynthesis, such as a triazine (psbAand gs+genes) and a benzonitrile (nitrilase gene). Przibilla et al.,Plant Cell 3: 169 (1991), describe the transformation of Chlamydomonaswith plasmids encoding mutant psbA genes. Nucleotide sequences fornitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, andDNA molecules containing these genes are available under ATCC AccessionNos. 53435, 67441 and 67442. Cloning and expression of DNA coding for aglutathione S-transferase is described by Hayes et al., Biochem. J. 285:173 (1992).

(D) Acetohydroxy acid synthase, which has been found to make plants thatexpress this enzyme resistant to multiple types of herbicides, has beenintroduced into a variety of plants (see, e.g., Hattori et al. (1995)Mol Gen Genet 246:419). Other genes that confer tolerance to herbicidesinclude: a gene encoding a chimeric protein of rat cytochrome P4507A1and yeast NADPH-cytochrome P450 oxidoreductase (Shiota et al. (1994)Plant Physiol Plant Physiol 106:17), genes for glutathione reductase andsuperoxide dismutase (Aono et al. (1995) Plant Cell Physiol 36:1687, andgenes for various phosphotransferases (Datta et al. (1992) Plant MolBiol 20:619).

(E) Protoporphyrinogen oxidase (protox) is necessary for the productionof chlorophyll, which is necessary for all plant survival. The protoxenzyme serves as the target for a variety of herbicidal compounds. Theseherbicides also inhibit growth of all the different species of plantspresent, causing their total destruction. The development of plantscontaining altered protox activity which are resistant to theseherbicides are described in U.S. Pat. Nos. 6,288,306 B1; 6,282,837 B1;and 5,767,373; and international Publication No. WO 01/12825, which areincorporated herein by reference in their entireties of all purposes.

3. Transgenes that Confer or Contribute to a Value-Added Trait, such as:

(A) Modified fatty acid metabolism, for example, by transforming a plantwith an antisense gene of stearoyl-ACP desaturase to increase stearicacid content of the plant. See Knultzon et al., Proc. Natl. Acad. Sci.USA 89: 2624 (1992).

(B) Decreased Phytate Content

(1) Introduction of a phytase-encoding gene would enhance breakdown ofphytate, adding more free phosphate to the transformed plant. Forexample, see Van Hartingsveldt et al., Gene 127: 87 (1993), for adisclosure of the nucleotide sequence of an Aspergillus niger phytasegene.

(2) A gene could be introduced that reduces phytate content. In maize,this, for example, could be accomplished, by cloning and thenreintroducing DNA associated with the single allele which is responsiblefor maize mutants characterized by low levels of phytic acid. See Raboyet al., Maydica 35: 383 (1990).

(C) Modified carbohydrate composition effected, for example, bytransforming plants with a gene coding for an enzyme that alters thebranching pattern of starch. See Shiroza et al., J. Bacteriol. 170: 810(1988) (nucleotide sequence of Streptococcus mutans fructosyltransferasegene), Steinmetz et al., Mol. Gen. Genet. 200: 220 (1985) (nucleotidesequence of Bacillus subtilis levansucrase gene), Pen et al.,Bio/Technology 10: 292 (1992) (production of transgenic plants thatexpress Bacillus licheniformis α-amylase), Elliot et al., Plant Molec.Biol. 21: 515 (1993) (nucleotide sequences of tomato invertase genes),Søgaard et al., J. Biol. Chem. 268: 22480 (1993) (site-directedmutagenesis of barley α-amylase gene), and Fisher et al., Plant Physiol.102: 1045 (1993) (maize endosperm starch branching enzyme II).

(D) Elevated oleic acid via FAD-2 gene modification and/or decreasedlinolenic acid via FAD-3 gene modification (see U.S. Pat. Nos.6,063,947; 6,323,392; and WO 93/11245).

4. Genes that Control Male-Sterility:

(A) Introduction of a deacetylase gene under the control of atapetum-specific promoter and with the application of the chemicalN-Ac-PPT (WO 01/29237).

(B) Introduction of various stamen-specific promoters (WO 92/13956, WO92/13957).

(C) Introduction of the barnase and the barstar gene (Paul et al. PlantMol. Biol. 19:611-622, 1992).

INDUSTRIAL APPLICABILITY

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch inthe wet-milling industry and maize flour in the dry-milling industry.The industrial applications of maize starch and flour are based onfunctional properties, such as viscosity, film formation, adhesiveproperties, and ability to suspend particles. The maize starch and flourhave application in the paper and textile industries. Other industrialuses include applications in adhesives, building materials, foundrybinders, laundry starches, explosives, oil-well muds, and other miningapplications.

Plant parts other than the grain of maize are also used in industry: forexample, stalks and husks are made into paper and wallboard and cobs areused for fuel and to make charcoal.

The seed of inbred maize line PH8DB, the plant produced from the inbredseed, the hybrid maize plant produced from the crossing of the inbred,hybrid seed, and various parts of the hybrid maize plant and transgenicversions of the foregoing, can be utilized for human food, livestockfeed, and as a raw material in industry.

Performance Examples of PH8DB

In the examples that follow, data from traits and characteristics ofinbred maize line PH8DB per se and in a hybrid are given and compared toother maize inbred lines and hybrids.

Inbred Comparison

The results in Table 2A compare inbred PH8DB to inbred PHK56. Theresults show that inbred PH8DB had significantly better early growth andearly stand counts than PHK56.

The results in Table 2B compare inbred PH8DB to inbred PH1CA. Theresults show that inbred PH8DB had significantly better early growththan PH1CA. Inbred PH8DB flowered significantly earlier than PH1CA.PH8DB also grew to a significantly shorter plant height than PH1CA.

The results in Table 2C compare inbred PH8DB to inbred PHKW3. Theresults show that inbred PH8DB had significantly better early growth andearly stand counts than PHKW3. Inbred PH8DB also flowered significantlylater than PHKW3.

The results in Table 2D compare inbred PH8DB to inbred PHR03. Theresults show that inbred PH8DB had significantly better early growth andearly stand counts than PHR03. Inbred PH8DB flowered significantlyearlier than inbred PHR03.

Hybrid Comparisons

The results in Table 3A compare a hybrid in which one of the parents isPH8DB and a second hybrid, 34G13. The results show that the hybridcontaining PH8DB had significantly higher yield and significantly highertest weight. The PH8DB hybrid also demonstrated significantly betterresistance to Gray leaf spot than hybrid 34G13.

The results in Table 3B compare a hybrid in which one of the parents isPH8DB and a second hybrid, 34B23. The results show that the hybridcontaining PH8DB had significantly better late root lodging andartificial brittle stalk scores than hybrid 34B23. The PH8DB hybrid alsodemonstrated significantly better scores than hybrid 34B23 for Gray leafspot, Northern leaf blight, and Anthracnose stalk rot resistance.

The results in Table 3C compare a hybrid in which one of the parents isPH8DB and a second hybrid, 34M94. The results show that the hybridcontaining PH8DB had significantly higher test weight. The PH8DB hybridalso demonstrated significantly better resistance to Northern leafblight.

The results in Table 3D compare a hybrid in which one of the parents isPH8DB and a second hybrid, 34G81. The results show that the hybridcontaining PH8DB had significantly higher yield and test weight. ThePH8DB hybrid also demonstrated significantly better early growth scoresthan hybrid 34G81.

The results in Table 3E compare a hybrid in which one of the parents isPH8DB and a second hybrid, 34H31. The results show that the hybridcontaining PH8DB had significantly later flowering.

TABLE 2A PAIRED INBRED COMPARISON REPORT Variety #1: PH8DB Variety #2:PHK56 YIELD YIELD MST EGRWTH ESTCNT TILLER BU/A 56# BU/A 56# PCT SCORECOUNT PCT Stat ABS % MN ABS ABS ABS ABS Mean1 147.2 133.7 20.7 5.7 23.26.6 Mean2 128.9 118.2 19.0 4.4 18.6 1.5 Locs 4 4 4 17 13 9 Reps 4 4 4 1713 9 Diff 18.3 15.5 −1.8 1.3 4.5 −5.1 Prob 0.398 0.401 0.249 0.001 0.0010.185 GDUSHD GDUSLK POLWT POLWT TASBLS TASSZ GDU GDU VALUE VALUE SCORESCORE Stat ABS ABS ABS % MN ABS ABS Mean1 145.2 146.6 113.8 76.0 6.4 5.3Mean2 145.9 149.6 155.3 106.9 9.0 4.9 Locs 52 53 21 21 5 46 Reps 52 5321 21 5 46 Diff −0.7 −3.0 −41.4 −31.0 −2.6 0.4 Prob 0.377 0.000 0.0010.001 0.073 0.073 PLTHT EARHT STAGRN STKLDG SCTGRN TEXEAR CM CM SCORE %NOT SCORE SCORE Stat ABS ABS ABS ABS ABS ABS Mean1 223.9 82.2 5.3 100.07.8 6.5 Mean2 234.2 82.2 6.3 94.4 7.0 5.0 Locs 35 3 21 5 14 4 Reps 35 321 5 14 4 Diff −10.3 −0.0 −1.0 5.6 0.8 1.5 Prob 0.005 1.000 0.047 0.3740.021 0.014 EARMLD BARPLT GLFSPT NLFBLT SLFBLT STWWLT SCORE % NOT SCORESCORE SCORE SCORE Stat ABS ABS ABS ABS ABS ABS Mean1 7.4 95.7 5.8 6.57.3 7.0 Mean2 6.6 96.6 6.5 4.0 4.3 7.0 Locs 8 22 10 2 2 1 Reps 8 22 10 22 1 Diff 0.8 −0.9 −0.7 2.5 3.0 0.0 Prob 0.423 0.532 0.226 0.126 1.000ANTROT FUSERS GIBERS DIPERS COMRST ECB1LF SCORE SCORE SCORE SCORE SCORESCORE Stat ABS ABS ABS ABS ABS ABS Mean1 4.0 6.3 9.0 6.1 6.0 7.0 Mean24.4 6.8 9.0 6.4 5.6 6.5 Locs 4 8 1 4 10 1 Reps 4 8 1 4 10 1 Diff −0.4−0.6 0.0 −0.3 0.4 0.5 Prob 0.796 0.391 0.604 0.494 HD RT ECB2SC SMTERTLDG LDG SCORE % NOT % NOT % NOT Stat ABS ABS ABS ABS Mean1 3.0 97.585.8 100.0 Mean2 4.0 97.6 100.0 100.0 Locs 1 3 2 1 Reps 1 3 2 1 Diff−1.0 −0.1 −14.2 0.0 Prob 0.980 0.386

TABLE 2B PAIRED INBRED COMPARISON REPORT Variety #1: PH8DB Variety #2:PH1CA YIELD YIELD MST EGRWTH ESTCNT TILLER GDUSHD BU/A 56# BU/A 56# PCTSCORE COUNT PCT GDU Stat ABS % MN ABS ABS ABS ABS ABS Mean1 136.5 116.121.8 6.0 21.6 6.5 141.3 Mean2 113.1 94.6 23.4 5.5 22.0 4.3 144.9 Locs 44 4 24 21 16 45 Reps 4 4 4 24 21 16 45 Diff 23.4 21.5 1.6 0.5 −0.3 −2.1−3.6 Prob 0.289 0.277 0.017 0.005 0.466 0.502 0.000 GDUSLK POLWT POLWTTASBLS TASSZ PLTHT EARHT GDU VALUE VALUE SCORE SCORE CM CM Stat ABS ABS% MN ABS ABS ABS ABS Mean1 142.7 122.6 109.7 6.6 5.6 222.5 81.3 Mean2146.9 196.3 167.3 8.6 6.2 229.8 97.8 Locs 46 4 4 8 39 39 4 Reps 46 4 4 839 39 4 Diff −4.2 −73.7 −57.7 −2.0 −0.6 −7.3 −16.5 Prob 0.000 0.1400.179 0.046 0.000 0.003 0.014 STAGRN STKLDG SCTGRN EARSZ TEXEAR EARMLDBARPLT SCORE % NOT SCORE SCORE SCORE SCORE % NOT Stat ABS ABS ABS ABSABS ABS ABS Mean1 5.0 100.0 7.7 5.0 6.5 6.3 98.1 Mean2 3.6 100.0 8.1 5.07.3 7.4 97.4 Locs 14 4 11 1 4 9 24 Reps 14 4 11 1 4 9 24 Diff 1.4 0.0−0.4 0.0 −0.8 −1.1 0.8 Prob 0.015 1.000 0.104 0.058 0.128 0.563 GLFSPTFUSERS DIPERS COMRST ERTLDG SCORE SCORE SCORE SCORE % NOT Stat ABS ABSABS ABS ABS Mean1 6.4 7.0 9.0 5.8 76.0 Mean2 6.2 7.8 9.0 6.2 88.0 Locs 56 1 6 1 Reps 5 6 1 6 1 Diff 0.2 −0.8 0.0 −0.3 −12.0 Prob 0.621 0.4480.661

TABLE 2C PAIRED INBRED COMPARISON REPORT Variety #1: PH8DB Variety #2:PHKW3 EGRWTH ESTCNT TILLER GDUSHD GDUSLK POLWT SCORE COUNT PCT GDU GDUVALUE Stat ABS ABS ABS ABS ABS ABS Mean1 6.1 20.5 8.9 145.4 146.3 125.0Mean2 5.4 16.1 0.0 138.7 143.3 180.5 Locs 14 10 9 30 31 7 Reps 14 10 930 31 7 Diff 0.7 4.4 −8.9 6.7 3.0 −55.5 Prob 0.019 0.004 0.017 0.0000.008 0.217 POLWT TASBLS TASSZ PLTHT EARHT STAGRN VALUE SCORE SCORE CMCM SCORE Stat % MN ABS ABS ABS ABS ABS Mean1 81.1 6.6 5.1 229.0 96.5 5.3Mean2 117.5 9.0 4.8 225.4 78.7 4.5 Locs 7 7 25 23 1 10 Reps 7 7 25 23 110 Diff −36.4 −2.4 0.4 3.6 17.8 0.8 Prob 0.191 0.031 0.214 0.522 0.235STKLDG SCTGRN TEXEAR EARMLD BARPLT GLFSPT % NOT SCORE SCORE SCORE % NOTSCORE Stat ABS ABS ABS ABS ABS ABS Mean1 100.0 8.0 6.5 7.7 97.8 5.7Mean2 100.0 7.0 7.5 6.5 98.4 4.7 Locs 4 9 2 6 16 3 Reps 4 9 2 6 16 3Diff 0.0 1.0 −1.0 1.2 −0.6 1.0 Prob 1.000 0.135 1.000 0.374 0.574 0.225FUSERS GIBERS DIPERS COMRST ERTLDG SCORE SCORE SCORE SCORE % NOT StatABS ABS ABS ABS ABS Mean1 7.8 9.0 9.0 5.5 95.7 Mean2 7.0 9.0 9.0 6.355.0 Locs 6 1 1 4 1 Reps 6 1 1 4 1 Diff 0.8 0.0 0.0 −0.8 40.7 Prob 0.5340.608

TABLE 2D PAIRED INBRED COMPARISON REPORT Variety #1: PH8DB Variety #2:PHR03 YIELD YIELD MST EGRWTH ESTCNT TILLER GDUSHD GDUSLK BU/A 56# BU/A56# PCT SCORE COUNT PCT GDU GDU Stat ABS % MN ABS ABS ABS ABS ABS ABSMean1 147.2 133.7 17.3 6.0 21.1 7.3 141.6 142.3 Mean2 124.3 112.0 17.55.5 17.9 3.6 149.1 152.6 Locs 4 4 7 23 16 13 35 36 Reps 4 4 7 23 16 1335 36 Diff 22.9 21.7 0.2 0.4 3.3 −3.7 −7.4 −10.3 Prob 0.078 0.093 0.7710.015 0.001 0.255 0.000 0.000 POLWT POLWT TASBLS TASSZ PLTHT EARHTSTAGRN STKLDG VALUE VALUE SCORE SCORE CM CM SCORE % NOT Stat ABS % MNABS ABS ABS ABS ABS ABS Mean1 94.0 70.1 7.2 5.6 226.0 85.1 4.4 100.0Mean2 165.2 125.4 8.5 5.9 233.3 99.1 4.8 100.0 Locs 4 4 6 29 27 2 10 3Reps 4 4 6 29 27 2 10 3 Diff −71.2 −55.2 −1.3 −0.3 −7.3 −14.0 −0.4 0.0Prob 0.061 0.058 0.082 0.048 0.026 0.170 0.443 1.000 SCTGRN EARSZ TEXEAREARMLD BARPLT GLFSPT SLFBLT FUSERS SCORE SCORE SCORE SCORE % NOT SCORESCORE SCORE Stat ABS ABS ABS ABS ABS ABS ABS ABS Mean1 8.1 5.0 6.3 7.398.9 6.5 6.0 6.6 Mean2 6.9 6.0 7.0 7.6 98.1 5.8 4.0 7.6 Locs 8 1 3 7 164 1 7 Reps 8 1 3 7 16 4 1 7 Diff 1.3 −1.0 −0.7 −0.3 0.8 0.8 2.0 −1.0Prob 0.011 0.184 0.654 0.398 0.215 0.234 DIPERS COMRST CLDTST CLDTSTKSZDCD ERTLDG ERTLPN SCORE SCORE PCT PCT PCT % NOT % NOT Stat ABS ABSABS % MN ABS ABS ABS Mean1 9.0 5.2 95.8 108.1 17.5 76.0 100.0 Mean2 9.05.8 90.3 101.7 3.5 59.1 20.0 Locs 1 5 4 4 4 1 1 Reps 1 5 4 4 4 1 1 Diff0.0 −0.6 5.5 6.5 14.0 16.9 80.0 Prob 0.501 0.341 0.342 0.163

TABLE 3A INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PH8DB Variety #2: 34G13 YIELD YIELD MST EGRWTH ESTCNT GDUSHDGDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT Stat ABS %MN % MN % MN % MN % MN % MN % MN Mean1 191.0 104.4 103.8 101.8 97.5100.1 99.9 100.5 Mean2 181.2 99.2 101.2 102.6 104.8 96.9 96.7 100.2 Locs137 137 138 15 3 34 25 222 Reps 137 137 138 15 3 34 25 222 Diff 9.8 5.2−2.6 −0.8 −7.3 3.3 3.2 0.2 Prob 0.000 0.000 0.000 0.920 0.240 0.0000.000 0.542 PLTHT EARHT STAGRN ERTLSC LRTLSC STKLDS STKLDG STKLDL IN INSCORE SCORE SCORE SCORE % NOT % NOT Stat % MN % MN % MN ABS ABS ABS % MN% MN Mean1 98.3 95.3 105.0 8.0 6.0 7.6 99.6 96.3 Mean2 91.0 93.4 101.59.0 9.0 8.3 103.6 103.8 Locs 41 41 46 1 1 29 11 30 Reps 41 41 46 1 1 2911 30 Diff 7.3 1.9 3.5 −1.0 −3.0 −0.7 −4.0 −7.5 Prob 0.000 0.178 0.4240.063 0.176 0.178 EBTSTK ABTSTK DRPEAR TSTWT GLFSPT NLFBLT SLFBLT GOSWLT% NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN % MN % MN ABSABS ABS ABS ABS Mean1 99.7 103.9 100.3 57.1 5.4 5.4 6.0 7.5 Mean2 101.892.6 99.9 56.5 4.2 5.3 5.5 7.0 Locs 1 7 2 102 15 7 2 1 Reps 1 7 2 102 157 2 1 Diff −2.0 11.2 0.4 0.6 1.1 0.1 0.5 0.5 Prob 0.096 0.500 0.0010.001 0.569 1.000 ANTROT CLN MDMCPX FUSERS GIBERS DIPERS ECB1LF ECB2SCSCORE SCORE SCORE SCORE SCORE SCORE SCORE SCORE Stat ABS ABS ABS ABS ABSABS ABS ABS Mean1 5.1 5.3 3.0 4.2 6.5 2.8 5.3 5.3 Mean2 5.5 3.5 2.5 4.06.5 1.8 6.4 6.3 Locs 12 2 2 7 1 4 2 15 Reps 12 2 2 7 1 4 2 15 Diff −0.41.8 0.5 0.2 0.0 1.0 −1.1 −0.9 Prob 0.600 0.258 0.500 0.682 0.295 0.2340.039 HD HSKCVR BRTSTK SMT ERTLPN LRTLPN STLPCN SCORE % NOT % NOT % NOT% NOT % NOT Stat ABS ABS ABS ABS ABS ABS Mean1 4.7 97.4 97.1 76.3 100.086.0 Mean2 5.0 99.2 96.9 88.8 95.6 84.5 Locs 15 2 5 2 9 21 Reps 15 2 5 29 21 Diff −0.3 −1.7 0.2 −12.5 4.4 1.4 Prob 0.301 0.006 0.960 0.344 0.3470.757

TABLE 3B INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PH8DB Variety #2: 34B23 YIELD YIELD MST EGRWTH ESTCNT GDUSHDGDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT Stat ABS %MN % MN % MN % MN % MN % MN % MN Mean1 189.6 103.8 103.4 104.8 98.8 99.399.3 100.4 Mean2 189.8 103.9 99.1 104.9 99.7 100.3 100.9 101.0 Locs 152152 153 18 4 31 22 236 Reps 152 152 153 18 4 31 22 236 Diff −0.2 −0.1−4.3 −0.1 −0.9 −0.9 −1.6 −0.7 Prob 0.940 0.940 0.000 0.988 0.768 0.0110.001 0.095 PLTHT EARHT STAGRN ERTLSC LRTLSC STKLDS STKLDG STKLDL IN INSCORE SCORE SCORE SCORE % NOT % NOT Stat % MN % MN % MN ABS ABS ABS % MN% MN Mean1 97.8 93.6 103.8 8.0 6.3 7.7 101.4 100.6 Mean2 98.7 94.0 96.29.0 4.7 6.3 90.3 96.0 Locs 41 41 50 1 6 41 17 29 Reps 41 41 50 1 6 41 1729 Diff −0.9 −0.4 7.6 −1.0 1.7 1.4 11.1 4.6 Prob 0.194 0.708 0.138 0.0110.002 0.060 0.422 EBTSTK ABTSTK DRPEAR TSTWT GLFSPT NLFBLT SLFBLT GOSWLT% NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN % MN % MN ABSABS ABS ABS ABS Mean1 99.7 101.7 100.4 57.3 5.3 5.4 6.0 7.5 Mean2 100.791.5 100.4 57.5 4.4 4.1 4.3 8.0 Locs 1 8 1 109 15 7 2 1 Reps 1 8 1 10915 7 2 1 Diff −1.0 10.1 0.0 −0.3 0.9 1.3 1.8 −0.5 Prob 0.003 0.127 0.0050.045 0.090 ANTROT CLN MDMCPX FUSERS GIBERS DIPERS ECB1LF ECB2SC SCORESCORE SCORE SCORE SCORE SCORE SCORE SCORE Stat ABS ABS ABS ABS ABS ABSABS ABS Mean1 5.1 5.3 3.0 4.2 6.5 2.8 5.3 5.2 Mean2 3.7 4.3 3.0 4.1 6.04.3 4.6 4.8 Locs 12 2 2 7 1 4 2 13 Reps 12 2 2 7 1 4 2 13 Diff 1.4 1.00.0 0.1 0.5 −1.5 0.8 0.4 Prob 0.043 0.295 1.000 0.805 0.314 0.656 0.426HD HSKCVR BRTSTK SMT ERTLPN LRTLPN STLPCN SCORE % NOT % NOT % NOT % NOT% NOT Stat ABS ABS ABS ABS ABS ABS Mean1 4.4 97.4 97.1 76.3 100.0 84.2Mean2 4.7 97.0 97.8 50.0 86.9 66.7 Locs 17 2 5 2 8 18 Reps 17 2 5 2 8 18Diff −0.3 0.4 −0.7 26.3 13.1 17.5 Prob 0.145 0.804 0.708 0.090 0.1570.000

TABLE 3C INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PH8DB Variety #2: 34M94 YIELD YIELD MST EGRWTH ESTCNT GDUSHDGDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT Stat ABS %MN % MN % MN % MN % MN % MN % MN Mean1 189.7 104.0 103.7 101.8 97.5100.1 99.9 100.4 Mean2 189.7 104.2 100.3 102.0 100.8 100.6 99.7 100.6Locs 140 140 141 15 3 34 25 226 Reps 140 140 141 15 3 34 25 226 Diff−0.1 −0.2 −3.4 −0.3 −3.3 −0.4 0.2 −0.2 Prob 0.972 0.815 0.000 0.9630.202 0.196 0.653 0.596 PLTHT EARHT STAGRN ERTLSC LRTLSC STKLDS STKLDGSTKLDL IN IN SCORE SCORE SCORE SCORE % NOT % NOT Stat % MN % MN % MN ABSABS ABS % MN % MN Mean1 98.2 95.0 105.8 8.0 6.0 7.5 99.2 96.3 Mean2 99.997.7 109.2 7.0 1.0 7.1 105.4 113.8 Locs 42 42 48 1 1 32 10 30 Reps 42 4248 1 1 32 10 30 Diff −1.7 −2.7 −3.4 1.0 5.0 0.4 −6.2 −17.5 Prob 0.0570.031 0.493 0.459 0.105 0.013 EBTSTK ABTSTK DRPEAR TSTWT GLFSPT NLFBLTSLFBLT GOSWLT % NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN% MN % MN ABS ABS ABS ABS ABS Mean1 99.7 103.9 100.3 57.2 5.4 5.4 6.07.5 Mean2 103.7 123.5 100.3 56.4 5.7 4.4 5.3 6.5 Locs 1 7 2 104 14 7 2 1Reps 1 7 2 104 14 7 2 1 Diff −4.0 −19.7 −0.0 0.8 −0.3 1.1 0.8 1.0 Prob0.041 0.295 0.000 0.267 0.041 0.205 ANTROT CLN MDMCPX FUSERS GIBERSDIPERS ECB1LF ECB2SC SCORE SCORE SCORE SCORE SCORE SCORE SCORE SCOREStat ABS ABS ABS ABS ABS ABS ABS ABS Mean1 5.1 5.3 3.0 4.2 6.5 2.8 5.35.3 Mean2 5.1 3.5 2.5 4.9 3.5 3.6 5.4 6.0 Locs 12 2 2 7 1 4 2 15 Reps 122 2 7 1 4 2 15 Diff −0.0 1.8 0.5 −0.7 3.0 −0.9 −0.1 −0.7 Prob 0.9760.395 1.000 0.035 0.553 0.874 0.087 HD HSKCVR BRTSTK SMT ERTLPN LRTLPNSTLPCN SCORE % NOT % NOT % NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABSMean1 4.4 97.4 97.1 76.3 100.0 86.0 Mean2 7.1 100.0 97.5 68.8 79.4 88.4Locs 17 2 5 2 9 21 Reps 17 2 5 2 9 21 Diff −2.7 −2.6 −0.4 7.5 20.6 −2.5Prob 0.000 0.196 0.805 0.656 0.064 0.544

TABLE 3D INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PH8DB Variety #2: 34G81 YIELD YIELD MST EGRWTH ESTCNT GDUSHDGDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT Stat ABS %MN % MN % MN % MN % MN % MN % MN Mean1 185.2 104.7 103.4 106.7 98.8100.5 100.4 100.8 Mean2 167.9 94.5 94.2 78.4 95.7 98.8 98.6 100.0 Locs88 88 89 18 4 22 17 150 Reps 88 88 89 18 4 22 17 150 Diff 17.3 10.2 −9.228.4 3.1 1.7 1.8 0.8 Prob 0.000 0.000 0.000 0.000 0.275 0.002 0.0000.136 PLTHT EARHT STAGRN ERTLSC LRTLSC STKLDS STKLDG STKLDL IN IN SCORESCORE SCORE SCORE % NOT % NOT Stat % MN % MN % MN ABS ABS ABS % MN % MNMean1 99.4 96.6 107.8 8.0 6.3 7.8 101.1 108.9 Mean2 95.9 97.3 97.8 7.05.2 7.1 109.8 102.8 Locs 24 24 31 1 6 37 15 21 Reps 24 24 31 1 6 37 1521 Diff 3.6 −0.7 10.0 1.0 1.2 0.6 −8.7 6.1 Prob 0.003 0.717 0.085 0.2560.167 0.043 0.403 EBTSTK ABTSTK DRPEAR TSTWT GLFSPT NLFBLT SLFBLT ANTROT% NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN % MN % MN ABSABS ABS ABS ABS Mean1 99.7 102.9 100.4 57.8 5.0 5.8 5.5 5.6 Mean2 100.6107.3 100.4 56.7 3.8 7.4 4.5 4.2 Locs 1 5 1 62 6 4 1 8 Reps 1 5 1 62 6 41 8 Diff −0.9 −4.4 0.0 1.1 1.2 −1.6 1.0 1.4 Prob 0.761 0.000 0.084 0.0230.305 HD CLN FUSERS DIPERS ECB1LF ECB2SC HSKCVR BRTSTK SMT SCORE SCORESCORE SCORE SCORE SCORE % NOT % NOT Stat ABS ABS ABS ABS ABS ABS ABS ABSMean1 4.5 3.7 3.3 5.0 5.3 4.5 97.4 95.9 Mean2 3.5 3.5 2.8 4.5 4.7 5.1100.0 100.0 Locs 1 3 2 1 3 8 2 3 Reps 1 3 2 1 3 8 2 3 Diff 1.0 0.2 0.50.5 0.7 −0.6 −2.6 −4.1 Prob 0.808 0.795 0.691 0.015 0.196 0.113

TABLE 3E INBREDS IN HYBRID COMBINATION REPORT Variety #1: HYBRIDCONTAINING PH8DB Variety #2: 34H31 YIELD YIELD MST EGRWTH ESTCNT GDUSHDGDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT Stat ABS %MN % MN % MN % MN % MN % MN % MN Mean1 189.6 103.9 103.3 104.6 98.8 99.999.8 100.5 Mean2 187.2 102.3 102.7 103.6 101.0 98.5 97.5 100.1 Locs 163163 164 22 4 40 27 252 Reps 163 163 164 22 4 40 27 252 Diff 2.4 1.5 −0.61.0 −2.3 1.3 2.4 0.4 Prob 0.162 0.114 0.329 0.855 0.330 0.000 0.0000.389 PLTHT EARHT STAGRN ERTLSC LRTLSC STKLDS STKLDG STKLDL IN IN SCORESCORE SCORE SCORE % NOT % NOT Stat % MN % MN % MN ABS ABS ABS % MN % MNMean1 98.1 94.6 103.3 8.0 6.3 7.7 101.3 96.8 Mean2 96.8 95.4 106.5 9.06.5 7.5 110.1 121.2 Locs 47 47 55 1 6 42 16 36 Reps 47 47 55 1 6 42 1636 Diff 1.3 −0.8 −3.3 −1.0 −0.2 0.2 −8.9 −24.3 Prob 0.017 0.505 0.4290.793 0.672 0.016 0.001 EBTSTK ABTSTK DRPEAR TSTWT GLFSPT NLFBLT SLFBLTGOSWLT % NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN % MN %MN ABS ABS ABS ABS ABS Mean1 99.7 101.7 100.3 57.2 5.3 5.4 6.0 7.5 Mean2100.7 97.5 98.5 57.8 5.1 6.9 5.0 8.0 Locs 1 8 3 118 16 7 2 1 Reps 1 8 3118 16 7 2 1 Diff −0.9 4.1 1.9 −0.6 0.3 −1.4 1.0 −0.5 Prob 0.522 0.1930.000 0.293 0.002 0.500 ANTROT CLN MDMCPX FUSERS GIBERS DIPERS ECB1LFECB2SC SCORE SCORE SCORE SCORE SCORE SCORE SCORE SCORE Stat ABS ABS ABSABS ABS ABS ABS ABS Mean1 5.1 5.3 3.0 4.2 6.5 2.8 5.3 5.3 Mean2 6.0 3.52.5 5.0 6.5 3.9 4.8 6.3 Locs 12 2 2 7 1 4 2 15 Reps 12 2 2 7 1 4 2 15Diff −0.9 1.8 0.5 −0.8 0.0 −1.1 0.6 −1.0 Prob 0.223 0.090 0.500 0.0810.135 0.686 0.013 HD LRTLPN STLPCN HSKCVR BRTSTK SMT ERTLPN SCORE % NOT% NOT % NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABS Mean1 4.4 97.4 97.176.3 100.0 86.0 Mean2 5.8 95.2 98.9 61.3 98.9 92.1 Locs 17 2 5 2 9 21Reps 17 2 5 2 9 21 Diff −1.4 2.2 −1.8 15.0 1.1 −6.2 Prob 0.000 0.3280.288 0.656 0.347 0.034Genetic Marker Profile Through SSR

The present invention comprises an inbred corn plant which ischaracterized by the molecular and physiological data presented hereinand in the representative sample of said line deposited with the ATCC.Further provided by the invention is a hybrid corn plant formed by thecombination of the disclosed inbred corn plant or plant cell withanother corn plant or cell and characterized by being heterozygous forthe molecular data of the inbred.

In addition to phenotypic observations, a plant can also be identifiedby its genotype. The genotype of a plant can be characterized through agenetic marker profile which can identify plants of the same variety ora related variety or be used to determine or validate a pedigree.Genetic marker profiles can be obtained by techniques such asRestriction Fragment Length Polymorphisms (RFLPs), Randomly AmplifiedPolymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction(AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence CharacterizedAmplified Regions (SCARs), Amplified Fragment Length Polymorphisms(AFLPs), Simple Sequence Repeats (SSRs) which are also referred to asMicrosatellites, and Single Nucleotide Polymorphisms (SNPs). Forexample, see Berry, Don, et al., “Assessing Probability of AncestryUsing Simple Sequence Repeat Profiles: Applications to Maize Hybrids andInbreds”, Genetics, 2002, 161:813-824, which is incorporated byreference herein in its entirety.

Particular markers used for these purposes are not limited to the set ofmarkers disclosed herein, but are envisioned to include any type ofmarker and marker profile which provides a means of distinguishingvarieties. In addition to being used for identification of Inbred LinePH8DB, a hybrid produced through the use of PH8DB, and theidentification or verification of pedigree for progeny plants producedthrough the use of PH8DB, the genetic marker profile is also useful inbreeding and developing single gene conversions.

Means of performing genetic marker profiles using SSR polymorphisms arewell known in the art. SSRs are genetic markers based on polymorphismsin repeated nucleotide sequences, such as microsatellites. A markersystem based on SSRs can be highly informative in linkage analysisrelative to other marker systems in that multiple alleles may bepresent. Another advantage of this type of marker is that, through useof flanking primers, detection of SSRs can be achieved, for example, bythe polymerase chain reaction (PCR), thereby eliminating the need forlabor-intensive Southern hybridization. The PCR™ detection is done byuse of two oligonucleotide primers flanking the polymorphic segment ofrepetitive DNA. Repeated cycles of heat denaturation of the DNA followedby annealing of the primers to their complementary sequences at lowtemperatures, and extension of the annealed primers with DNA polymerase,comprise the major part of the methodology.

Following amplification, markers can be scored by gel electrophoresis ofthe amplification products. Scoring of marker genotype is based on thesize of the amplified fragment as measured by molecular weight (MW)rounded to the nearest integer. While variation in the primer used or inlaboratory procedures can affect the reported molecular weight, relativevalues should remain constant regardless of the specific primer orlaboratory used. When comparing lines it is preferable if all SSRprofiles are performed in the same lab. The SSR analyses reported hereinwere conducted in-house at Pioneer Hi-Bred. An SSR service is availableto the public on a contractual basis by Paragen (formerly Celera AgGen)in Research Triangle Park, N.C.

Primers used for the SSRs reported herein are publicly available and maybe found in the Maize GDB using the World Wide Web prefix followed byagron.missouri.edu/maps.html (maintained by the USDA AgriculturalResearch Service, in Sharopova et al. (Plant Mol. Biol.48(5-6):463-481), Lee et al. (Plant Mol. Biol. 48(5-6); 453-461), orreported herein. Some marker information may be available from Paragen.

Map information is provided in centimorgans (cM) and based on acomposite map developed by Pioneer Hi-Bred. This composite map wascreated by identifying common markers between various maps and usinglinear regression to place the intermediate markers. The reference mapused was UMC98. Map positions for the SSR markers reported herein willvary depending on the mapping population used. Any chromosome numbersreported in parenthesis represent other chromosome locations for suchmarker that have been reported in the literature or on the Maize GDB.Map positions are available on the Maize GDB for a variety of differentmapping populations.

TABLE 4 SSR Profile PH8DB Locus Chrom # Position mwt PHI056 1 4.25 252PHI427913 1 26.71 132 BNLG1014 1 29.8 126 BNLG1429 1 30.68 213 BNLG16271 34.03 208 BNLG1127 1 38.07 119 BNLG1484 1 53.32 148 BNLG439 1 62.42235 BNLG1203 1 62.42 307 PHI339017 1 70.05 148 BNLG1886 1 91.64 141BNLG2086 1 94.5 236 BNLG1057 1 142.56 253 BNLG1615 1 142.74 223 BNLG15561 150.53 197 PHI326957 1 166.54 122 PHI002 1 168.21 72 PHI323065 1177.39 331 PHI335539 1 178.84 91 PHI011 1 190.9 230 BNLG1331 1 193.48124 BNLG1597 1 199.42 191 BNLG1720 1 199.44 244 PHI308707 1 211.59 134PHI265454 1 221.46 221 PHI227562 1 242.7 322 PHI109275 1 unknown 135BNLG1832 1 unknown 218 BNLG1083 1 unknown 207 PHI96100 2 6.99 284BNLG1017 2 21.79 197 BNLG2277 2 55.07 295 BNLG1064 2 64.21 191 PHI1096422 69.93 142 BNLG1909 2 76.87 298 BNLG1018 2 77.92 142 BNLG1396 2 120.07136 BNLG1138 2 121.18 227 PHI328189 2 145.57 124 BNLG2237 2 148.65 219PHI251315 2 149.77 127 PHI127 2 152.84 124 PHI101049 2 207.93 230PHI435417 2 302.56 216 BNLG1520 2 375.32 298 PHI402893 2 unknown 216PHI090 2 unknown 141 PHI083 2 unknown 126 BNLG1831 2 unknown 193BNLG1141 2 unknown 155 PHI453121 3 0.2 214 PHI404206 3 2.2 305 PHI1041273 5.68 165 BNLG1144 3 23.52 118 BNLG1647 3 33.98 166 BNLG1523 3 34.3 268PHI243966 3 52.24 215 PHI374118 3 53.66 230 BNLG1452 3 58.58 128BNLG1019 3 58.65 158 PHI053 3 67.9 169 PHI102228 3 104.98 139 BNLG1951 3108.98 130 BNLG1160 3 110.2 225 PHI193225 3 159.24 137 PHI029 3 unknown160 BNLG2241 3 unknown 119 BNLG1035 3 unknown 104 PHI295450 4 16.87 187PHI079 4 65.46 181 BNLG1937 4 65.49 230 BNLG1265 4 67.31 216 BNLG1755 491.45 219 BNLG1189 4 108.12 133 BNLG2244 4 122.51 202 PHI314704 4 159.67139 PHI438301 4 819.88 210 PHI076 4 unknown 173 PHI072 4 unknown 163BNLG1006 5 15.9 219 PHI396160 5 76.45 300 PHI109188 5 77.97 170 BNLG6535 88.43 154 BNLG1208 5 94.95 121 BNLG1892 5 97.9 160 PHI330507 5 102.23135 PHI333597 5 103.48 216 BNLG1118 5 149.53 84 BNLG1711 5 178.37 180PHI423796 6 31.29 131 PHI452693 6 98.06 125 BNLG1041 6 98.1 197 BNLG11746 99.41 222 PHI364545 6 126.24 138 PHI299852 6 129.9 123 PHI070 6 129.983 BNLG1759 6 129.9 151 PHI034 7 54.75 141 BNLG2271 7 95.38 223PHI328175 7 100.36 124 PHI260485 7 134.62 288 PHI069 7 137.5 197 PHI1167 149.22 172 PHI420701 8 24.32 294 BNLG2082 8 55.3 175 PHI100175 8 60.43148 PHI115 8 64.03 304 PHI121 8 66.43 101 BNLG1176 8 79.72 221 BNLG11528 111.61 124 BNLG1065 8 127.89 241 PHI279122 8 163.03 223 BNLG1056 8193.84 97 PHI015 8 210.92 97 PHI233376 8 219.36 142 BNLG2122 9 32.11 222BNLG1012 9 84.23 171 PHI032 9 86.67 240 PHI448880 9 126.07 187 PHI2366549 157.45 120 PHI108411 9 169.83 129 PHI033 9 unknown 252 BNLG1375 9unknown 168 BNLG1129 9 unknown 300 PHI041 10 9.6 205 PHI059 10 40.55 156PHI96342 10 52.8 256 BNLG1079 10 62.12 172 PHI050 10 63 86 PHI062 1069.31 164 BNLG1074 10 85.74 174 PHI301654 10 91.26 132 PHI323152 10117.1 137 BNLG1450 10 126.36 192 BNLG1185 10 142.38 154 BNLG1597 5 (1,6) 154.8 216

The SSR profile of Inbred PH8DB can be used to identify hybridscomprising PH8DB as a parent, since such hybrids will comprise the samealleles as PH8DB. Because an inbred is essentially homozygous at allrelevant loci, an inbred should, in almost all cases, have only oneallele at each locus. In contrast, a genetic marker profile of a hybridshould be the sum of those parents, e.g., if one inbred parent had theallele 168 (base pairs) at a particular locus, and the other inbredparent had 172 the hybrid is 168.172 (heterozygous) by inference.Subsequent generations of progeny produced by selection and breeding areexpected to be of genotype 168 (homozygous), 172 (homozygous), or168.172 for that locus position. When the F1 plant is used to produce aninbred, the locus should be either 168 or 172 for that position.

In addition, plants and plant parts substantially benefiting from theuse of PH8DB in their development such as PH8DB comprising a single geneconversion, transgene, or genetic sterility factor, may be identified byhaving a molecular marker profile with a high percent identity to PH8DB.Such a percent identity might be 98%, 99%, 99.5% or 99.9% identical toPH8DB.

The SSR profile of PH8DB also can be used to identify essentiallyderived varieties and other progeny lines developed from the use ofPH8DB, as well as cells and other plant parts thereof. Progeny plantsand plant parts produced using PH8DB may be identified by having amolecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%, 55%,60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5% geneticcontribution from inbred line PH8DB. Unique SSR Profiles

While determining the SSR genetic marker profile of the inbredsdescribed supra, several unique SSR profile loci sets were identifiedwhich did not appear in either parent of such inbred.

Such unique SSR profiles may arise during the breeding process fromrecombination or mutation. A combination of several unique allelesprovides a means of identifying an inbred, a hybrid produced from suchinbred, and progeny produced from such inbred and comprising such uniqueSSR profile, regardless of the number of generations or breeding cyclesremoved. Such progeny may be further characterized as being within apedigree distance of PH8DB, such as within 1,2,3,4 or 5 or lesscross-pollinations to a maize plant other than PH8DB or a plant that hasPH8DB as a progenitor. Further unique molecular profiles may beidentified with other molecular tools such as SNPs and RFLPs.

Each genetic marker profile shown in Table 5 represents a novel groupingof alleles unique to this inbred. For each of the unique SSR profilesfound, referred to as a “loci set”, comparative searches of the SSRprofiles of over 1780 other inbreds were performed. No publicly knowninbreds were identified as containing an SSR loci set disclosed in Table5. The primers used to detect the unique SSR profiles are a subset ofthose disclosed previously herein, with primers for any additionalmarkers noted in the table. Map locations for such additional markerswere determined by Pioneer Hi-Bred in Johnston, Iowa.

TABLE 5 Unique SSR Profile PH8DB Loci Chrom Set # Locus Position mwtLprimer Rprimer A 1 BNLG1484 53.32 148 BNLG439 62.42 235 BNLG1203 62.42307 PHI339017 70.05 148 BNLG1886 91.64 141 BNLG2086 94.5 236 B 1BNLG1057 142.56 253 BNLG1615 142.74 223 BNLG1556 150.53 197 PHI326957166.54 122 SEQ ID SEQ ID NO: 1 NO: 2 PHI002 168.21 72 C 8 BNLG1176 79.72221 BNLG1152 111.61 124 BNLG1065 127.89 241 PHI279122 163.03 223 SEQ IDSEQ ID NO: 3 NO: 4

DEPOSITS

Applicants have made a deposit of at least 2500 seeds of Inbred MaizeLine PH8DB with the American Type Culture Collection (ATCC), Manassas,Va. 20110 USA, ATCC Deposit No. PTA-4685. The seeds deposited with theATCC on Sep. 18, 2002 were taken from the deposit maintained by PioneerHi-Bred International, Inc., 7250 NW 62nd Avenue, Johnston, Iowa50131-0552 since prior to the filing date of this application. Access tothis deposit will be available during the pendency of the application tothe Commissioner of Patents and Trademarks and persons determined by theCommissioner to be entitled thereto upon request. Upon allowance of anyclaims in the application, the Applicants will make the depositavailable to the public pursuant to 37 C.F.R. § 1.808. This deposit ofthe Inbred Maize Line PH8DB will be maintained in the ATCC depository,which is a public depository, for a period of 30 years, or 5 years afterthe most recent request, or for the enforceable life of the patent,whichever is longer, and will be replaced if it becomes nonviable duringthat period. Additionally, Applicants have satisfied all therequirements of 37 C.F.R. §§ 1.801-1.809, including providing anindication of the viability of the sample upon deposit. Applicants haveno authority to waive any restrictions imposed by law on the transfer ofbiological material or its transportation in commerce. Applicants do notwaive any infringement of his rights granted under this patent or underthe Plant Variety Protection Act (7 USC 2321 et seq.). U.S. PlantVariety Protection of Inbred Maize Line PH8DB has been issued under PVPNo. 200200188. Unauthorized seed multiplication prohibited. U.S.Protected Variety.

All publications, patents and patent applications mentioned in thespecification are indicative of the level of those skilled in the art towhich this invention pertains. All such publications, patents and patentapplications are incorporated by reference herein to the same extent asif each was specifically and individually indicated to be incorporatedby reference herein.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas single gene conversions and mutations, somoclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

1. A seed comprising at least one set of the chromosomes of maize inbredline PH8DB, representative seed of said line having been deposited underATCC Accession No. PTA-4685.
 2. A maize plant produced by growing theseed of claim
 1. 3. A maize plant part of the maize plant of claim
 2. 4.An F1 hybrid maize seed produced by crossing a plant of maize inbredline designated PH8DB, representative seed of said line having beendeposited under ATCC Accession No. PTA-4685, with a different maizeplant and harvesting the resultant F1 hybrid maize seed, wherein said F1hybrid maize seed comprises two sets of chromosomes and one set of thechromosomes is the same as maize inbred line PH8DB.
 5. A maize plantproduced by growing an F1 hybrid maize seed of claim
 4. 6. A maize plantpart of the maize plant of claim
 5. 7. An F1 hybrid maize seedcomprising an inbred maize plant cell of inbred maize line PH8DB,representative seed of said line having been deposited under ATCCAccession No. PTA-4685.
 8. A maize plant produced by growing the F1hybrid maize seed of claim
 7. 9. The F1 hybrid maize seed of claim 7wherein the inbred maize plant cell comprises two sets of chromosomes ofmaize inbred line PH8DB.
 10. A maize plant produced by growing the F1hybrid maize seed of claim
 9. 11. The seed of claim 1, wherein said setof chromosomes comprise all of the alleles of inbred line PH8DB at theSSR loci listed in Table
 4. 12. The F1 hybrid maize seed of claim 4wherein the set of chromosomes that is the same as maize inbred linePH8DB comprises all of the alleles of inbred line PH8DB at the SSR locilisted in Table
 4. 13. A process of introducing a desired trait intomaize inbred line PH8DB comprising: (a) crossing PH8DB plants grown fromPH8DB seed, representative seed of which has been deposited under ATCCAccession No: PTA-4685, with plants of another maize line that comprisea desired trait to produce F1 progeny plants, wherein the desired traitis selected from the group consisting of waxy starch, male sterility,herbicide resistance, insect resistance, bacterial disease resistance,fungal disease resistance, and viral disease resistance; (b) selectingF1 progeny plants that have the desired trait to produce selected F1progeny plants; (c) crossing the selected progeny plants with the PH8DBplants to produce backcross progeny plants; (d) selecting for backcrossprogeny plants that have the desired trait and the alleles of inbredline PH8DB at the SSR loci listed in Table 4 to produce selectedbackcross progeny plants; and (e) repeating steps (c) and (d) to producebackcross progeny plants that comprise the desired trait and comprise atleast 95% of the alleles of inbred line PH8DB at the SSR loci listed inTable
 4. 14. A plant produced by the process of claim 13, wherein theplant comprises at least 95% of the alleles of inbred line PH8DB at theSSR loci listed in Table
 4. 15. A maize plant having all thephysiological and morphological characteristics of inbred line PH8DB,wherein a sample of the seed of inbred line PH8DB was deposited underATCC Accession Number PTA-4685.
 16. A process of producing maize seed,comprising crossing a first parent maize plant with a second parentmaize plant, wherein one or both of the first or the second parent maizeplants is the plant of claim 15, wherein seed is allowed to form. 17.The maize seed produced by the process of claim
 16. 18. The maize seedof claim 17, wherein the maize seed is hybrid seed.
 19. A hybrid maizeplant, or its parts, produced by growing said hybrid seed of claim 18.20. A cell of the maize plant of claim
 15. 21. A seed comprising thecell of claim
 20. 22. The maize plant of claim 15, further defined ashaving a genome comprising a single locus gene conversion.
 23. The maizeplant of claim 22, wherein the single gene was stably inserted into themaize genome by transformation.
 24. The maize plant of claim 22, whereinthe gene is selected from the group consisting of a dominant allele anda recessive allele.
 25. The maize plant of claim 22, wherein the geneconfers a trait selected from the group consisting of herbicidetolerance; insect resistance; resistance to bacterial, fungal, nematodeor viral disease; waxy starch; male sterility and restoration of malefertility.
 26. The maize plant of claim 15, wherein said plant isfurther defined as comprising a gene conferring male sterility.
 27. Themaize plant of claim 15, wherein said plant is further defined ascomprising a transgene conferring a trait selected from the groupconsisting of male sterility, herbicide resistance, insect resistanceand disease resistance.
 28. A method of producing a maize plantcomprising the steps of: (a) growing a progeny plant produced bycrossing the plant of claim 15 with a second maize plant; (b) crossingthe progeny plant with itself or a different plant to produce a seed ofa progeny plant of a subsequent generation; (c) growing a progeny plantof a subsequent generation from said seed and crossing the progeny plantof a subsequent generation with itself or a different plant; and (d)repeating steps (b) and (c) for an additional 0-5 generations to producea maize plant.
 29. The method of claim 28, wherein the produced maizeplant is an inbred maize plant.
 30. The method of claim 29, furthercomprising the step of crossing the inbred maize plant with a second,distinct inbred maize plant to produce an F1 hybrid maize plant.
 31. Amethod for developing a second maize plant in a maize plant breedingprogram comprising applying plant breeding techniques to a first maizeplant, or parts thereof, wherein said first maize plant is the maizeplant of claim 15, and wherein application of said techniques results indevelopment of said second maize plant.
 32. The method for developing amaize plant in a maize plant breeding program of claim 31 wherein plantbreeding techniques are selected from the group consisting of recurrentselection, backcrossing, pedigree breeding, restriction fragment lengthpolymorphism enhanced selection, genetic marker enhanced selection, andtransformation.
 33. A method of plant breeding comprising the steps of:(a) obtaining a molecular marker profile of maize inbred line PH8DB,representative seed of said line having been deposited under ATCCAccession No. PTA-4685; (b) obtaining an F1 hybrid seed for which themaize plant of claim 11 is a parent; (c) crossing a plant grown from theF1 hybrid seed with a different maize plant; and (d) selecting progenythat possess said molecular marker profile of PH8DB.